Hand-held postcard printer

ABSTRACT

A digital camera comprises an image sensor device for sensing an image. A processor processes the sensed image. A pagewidth printhead prints the sensed image. An ink supply arrangement supplies ink to the print head and the image is printed on print media from a supply of print media. The supply of print media is pre-marked with tokens designating that postage has been paid so that each image printed out on the print media has one such token associated with it.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent application Ser. No. 09/663,153, filed on Sep. 15, 2000, now Issued U.S. Pat. No. 6,738,096, which is a divisional of and claims the benefit of U.S. patent application Ser. No. 09/113,086 filed on Jul. 10, 1998, now abandoned.

FIELD OF THE INVENTION

The present invention relates substantially to the concept of a disposable camera having instant printing capabilities and in particular, discloses a method integrating the electronic components of a camera system.

BACKGROUND OF THE INVENTION

Recently, the concept of a “single use” disposable camera has become an increasingly popular consumer item. Disposable camera systems presently on the market normally include an internal film roll and a simplified gearing mechanism for traversing the film roll across an imaging system including a shutter and lensing system. The user, after utilizing a single film roll returns the camera system to a film development center for processing. The film roll is taken out of the camera system and processed and the prints returned to the user. The camera system is then able to be re-manufactured through the insertion of a new film roll into the camera system, the replacement of any worn or wearable parts and the re-packaging of the camera system in accordance with requirements. In this way, the concept of a single use “disposable” camera is provided to the consumer.

Recently, a camera system has been proposed by the present applicant which provides for a handheld camera device having an internal print head, image sensor and processing means such that images sense by the image sensing means, are processed by the processing means and adapted to be instantly printed out by the printing means on demand. The proposed camera system further discloses a system of internal “print rolls” carrying print media such as film on to which images are to be printed in addition to ink for supplying to the printing means for the printing process. The print roll is further disclosed to be detachable and replaceable within the camera system.

Unfortunately, such a system is likely to only be constructed at a substantial cost and it would be desirable to provide for a more inexpensive form of instant camera system which maintains a substantial number of the quality aspects of the aforementioned arrangement.

It would be further advantageous to provide for the effective interconnection of the sub components of a camera system.

SUMMARY OF THE INVENTION

According to the invention, there is provided a recyclable, one-time use, print on demand, digital camera comprising:

an image sensor device for sensing an image;

a processing means for processing said sensed image;

a pagewidth print head for printing said sensed image;

an ink supply means for supplying ink to the print head; and

a supply of print media on to which said image is printed, the supply of print media being pre-marked with tokens designating that postage has been paid so that each image printed out on the print media has one such token associated with it.

Preferably, the supply of print media is in the form of a roll, the tokens being pre-printed at regularly spaced intervals on one surface of the print media.

Each token may have an address zone and a blank zone for writing associated with it on said one surface to provide a postcard effect.

Each image may be printed on an opposed surface of the print media.

The token may be in the form of a postage stamp which is in a currency of a country in which the camera is bought, with a notice to that effect being carried on an exterior of that camera. Preferably, the camera has a sleeve placed about a casing of the camera. The notice may then be carried on the sleeve of the camera.

BRIEF DESCRIPTION OF THE DRAWINGS

Not with standing any other forms which may fall within the scope of the present invention, preferred forms of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:

FIG. 1 illustrates a front perspective view of the assembled camera of the preferred embodiment;

FIG. 2 illustrates a rear perspective view, partly exploded, of the preferred embodiment;

FIG. 3 is a perspective view of the chassis of the preferred embodiment;

FIG. 4 is a perspective view of the chassis illustrating mounting of electric motors;

FIG. 5 is an exploded perspective view of the ink supply mechanism of the preferred embodiment;

FIG. 6 is a rear perspective view of the assembled form of the ink supply mechanism of the preferred embodiment;

FIG. 7 is a front perspective view of the assembled form of the ink supply mechanism of the preferred embodiment;

FIG. 8 is an exploded perspective view of the platten unit of the preferred embodiment;

FIG. 9 is a perspective view of the assembled form of the platten unit;

FIG. 10 is also a perspective view of the assembled form of the platten unit;

FIG. 11 is an exploded perspective view of the printhead recapping mechanism of the preferred embodiment;

FIG. 12 is a close up, exploded perspective view of the recapping mechanism of the preferred embodiment;

FIG. 13 is an exploded perspective view of the ink supply cartridge of the preferred embodiment;

FIG. 14 is a close up, perspective view, partly in section, of the internal portions of the ink supply cartridge in an assembled form;

FIG. 15 is a schematic block diagram of one form of chip layer of the image capture and processing chip of the preferred embodiment;

FIG. 16 is an exploded perspective view illustrating the assembly process of the preferred embodiment;

FIG. 17 illustrates a front exploded perspective view of the assembly process of the preferred embodiment;

FIG. 18 illustrates a perspective view of the assembly process of the preferred embodiment;

FIG. 19 illustrates a perspective view of the assembly process of the preferred embodiment;

FIG. 20 is a perspective view illustrating the insertion of the platten unit in the preferred embodiment;

FIG. 21 illustrates the interconnection of the electrical components of the preferred embodiment;

FIG. 22 illustrates the process of assembling the preferred embodiment; and

FIG. 23 is a perspective view further illustrating the assembly process of the preferred embodiment.

DESCRIPTION OF PREFERRED AND OTHER EMBODIMENTS

Turning initially simultaneously to FIG. 1 and FIG. 2 there are illustrated perspective views of an assembled camera constructed in accordance with the preferred embodiment with FIG. 1 showing a front perspective view and FIG. 2 showing a rear perspective view. The camera 1 includes a paper or plastic film jacket 2 which can include simplified instructions 3 for the operation of the camera system 1. The camera system 1 includes a first “take” button 4 which is depressed to capture an image. The captured image is output via output slot 6. A further copy of the image can be obtained through depressing a second “printer copy” button 7 whilst an LED light 5 is illuminated. The camera system also provides the usual viewfinder 8 in addition to a CCD image capture/lensing system 9.

The camera system 1 provides for a standard number of output prints after which the camera system 1 ceases to function. A prints left indicator slot 10 is provided to indicate the number of remaining prints. A refund scheme at the point of purchase is assumed to be operational for the return of used camera systems for recycling.

Turning now to FIG. 3, the assembly of the camera system is based around an internal chassis 12 which can be a plastic injection molded part. A pair of paper pinch rollers 28, 29 utilized for de-curling are snap fitted into corresponding frame holes eg. 26, 27.

As shown in FIG. 4, the chassis 12 includes a series of mutually opposed prongs e.g. 13, 14 into which is snapped fitted a series of electric motors 16, 17. The electric motors 16, 17 can be entirely standard with the motor 16 being of a stepper motor type. The motors 16,17 include cogs 19, 20 for driving a series of gear wheels. A first set of gear wheels is provided for controlling a paper cutter mechanism and a second set is provided for controlling print roll movement.

Turning next to FIGS. 5 to 7, there is illustrated an ink supply mechanism 40 utilized in the camera system. FIG. 5 illustrates a rear exploded perspective view, FIG. 6 illustrates a rear assembled perspective view and FIG. 7 illustrates a front assembled view. The ink supply mechanism 40 is based around an ink supply cartridge 42 which contains printer ink and a print head mechanism for printing out pictures on demand. The ink supply cartridge 42 includes a side aluminum strip 43 which is provided as a shear strip to assist in cutting images from a paper roll.

A dial mechanism 44 is provided for indicating the number of “prints left”. The dial mechanism 44 is snap fitted through a corresponding mating portion 46 so as to be freely rotatable.

As shown in FIG. 6, the mechanism 40 includes a flexible PCB strip 47 which interconnects with the print head and provides for control of the print head. The interconnection between the Flex PCB strip and an image sensor and print head chip can be via Tape Automated Bonding (TAB) strips 51, 58. A molded aspherical lens and aperture shim 50 (FIG. 5) is also provided for imaging an image onto the surface of the image sensor chip normally located within cavity 53 and a light box module or hood 52 is provided for snap fitting over the cavity 53 so as to provide for proper light control. A series of decoupling capacitors e.g. 34 can also be provided. Further a plug 45 (FIG. 7) is provided for re-plugging ink holes after refilling. A series of guide prongs e.g. 55-57 are further provided for guiding the flexible PCB strip 47.

The ink supply mechanism 40 interacts with a platten unit 60 which guides print media under a printhead located in the ink supply mechanism. FIG. 8 shows an exploded view of the platten unit 60, while FIGS. 9 and 10 show assembled views of the platten unit. The platten unit 60 includes a first pinch roller 61 which is snap fitted to one side of a platten base 62. Attached to a second side of the platten base 62 is a cutting mechanism 63 which traverses the platen unit 60 by means of a rod 64 having a screw thread which is rotated by means of cogged wheel 65 which is also fitted to the platten base 62. The screw threaded rod 64 mounts a block 67 which includes a cutting wheel 68 fastened via a fastener 69. Also mounted to the block 67 is a counter actuator which includes a pawl. The pawl 71 acts to rotate the dial mechanism 44 of FIG. 6 upon the return traversal of the cutting wheel. As shown previously in FIG. 6, the dial mechanism 44 includes a cogged surface which interacts with pawl 71 thereby maintaining a count of the number of photographs by means of numbers embossed on the surface of dial mechanism 44. The cutting mechanism 63 is inserted into the platten base 62 by means of a snap fit via clips e.g. 74.

The platen unit 60 includes an internal recapping mechanism 80 for recapping the printhead when not in use. The recapping mechanism 80 includes a sponge portion 81 and is operated via a solenoid coil so as to provide for recapping of the print head. In the preferred embodiment, there is provided an inexpensive form of printhead re-capping mechanism provided for incorporation into a handheld camera system so as to provide for printhead re-capping of an inkjet printhead.

FIG. 11 illustrates an exploded view of the recapping mechanism whilst FIG. 12 illustrates a close up of the end portion thereof The re-capping mechanism 80 is structured around a solenoid including a 16 turn coil 75 which can comprise insulated wire. The coil 75 is turned around a first stationery solenoid arm 76 which is mounted on a bottom surface of the platen base 62 (FIG. 8) and includes a post portion 77 to magnify effectiveness of operation. The arm 76 can comprise a ferrous material.

A second moveable arm 78 of the solenoid actuator is also provided. The arm 78 is moveable and is also made of ferrous material. Mounted on the arm is a sponge portion surrounded by an elastomer strip 79. The elastomer strip 79 is of a generally arcuate cross-section and acts as a leaf spring against the surface of the printhead ink supply cartridge 42 (FIG. 5) so as to provide for a seal against the surface of the printhead ink supply cartridge 42. In the quiescent position an elastomer spring unit 87, 88 acts to resiliently deform the elastomer seal 79 against the surface of the ink supply unit 42.

When it is desired to operate the printhead unit, upon the insertion of paper, the solenoid coil 75 is activated so as to cause the arm 78 to move down to be adjacent to the end plate 76. The arm 78 is held against end plate 76 while the printhead is printing by means of a small “keeper current” in coil 75. Simulation results indicate that the keeper current can be significantly less than the actuation current. Subsequently, after photo printing, the paper is guillotined by the cutting mechanism 63 of FIG. 8 acting against aluminum strip 43, and rewound so as to clear the area of the re-capping mechanism 80. Subsequently, the current is turned off and springs 87, 88 return the arm 78 so that the elastomer seal is again resting against the printhead ink supply cartridge.

It can be seen that the preferred embodiment provides for a simple and inexpensive means of re-capping a printhead through the utilization of a solenoid type device having a long rectangular form. Further, the preferred embodiment utilizes minimal power in that currents are only required whilst the device is operational and additionally, only a low keeper current is required whilst the printhead is printing.

Turning next to FIGS. 13 and 14, FIG. 13 illustrates an exploded perspective of the ink supply cartridge 42 whilst FIG. 14 illustrates a close up sectional view of a bottom of the ink supply cartridge with the printhead unit in place. The ink supply cartridge 42 is based around a pagewidth printhead 102 which comprises a long slither of silicon having a series of holes etched on the back surface for the supply of ink to a front surface of the silicon wafer for subsequent ejection via a micro electromechanical system. The form of ejection can be many different forms such as those set out in the tables below.

Of course, many other inkjet technologies, as referred to the attached tables below, can also be utilized when constructing a printhead unit 102. The fundamental requirement of the ink supply cartridge 42 is the supply of ink to a series of color channels etched through the back surface of the printhead 102. In the description of the preferred embodiment, it is assumed that a three color printing process is to be utilized so as to provide full color picture output. Hence, the print supply unit includes three ink supply reservoirs being a cyan reservoir 104, a magenta reservoir 105 and a yellow reservoir 106. Each of these reservoirs is required to store ink and includes a corresponding sponge type material 107-109 which assists in stabilizing ink within the corresponding ink channel and inhibiting the ink from sloshing back and forth when the printhead is utilized in a handheld camera system. The reservoirs 104, 105, 106 are formed through the mating of first exterior plastic piece 110 and a second base piece 111.

At a first end 118 of the base piece 111 a series of air inlet 113-115 are provided. Each air inlet leads to a corresponding winding channel which is hydrophobically treated so as to act as an ink repellent and therefore repel any ink that may flow along the air inlet channel. The air inlet channel further takes a convoluted path assisting in resisting any ink flow out of the chambers 104-106. An adhesive tape portion 117 is provided for sealing the channels within end portion 118.

At the top end, there is included a series of refill holes (not shown) for refilling corresponding ink supply chambers 104, 105, 106. A plug 121 is provided for sealing the refill holes.

Turning now to FIG. 14, there is illustrated a close up perspective view, partly in section through the ink supply cartridge 42 of FIG. 13 when formed as a unit. The ink supply cartridge includes the three color ink reservoirs 104, 105, 106 which supply ink to different portions of the back surface of printhead 102 which includes a series of apertures 128 defined therein for carriage of the ink to the front surface.

The ink supply cartridge 42 includes two guide walls 124, 125 which separate the various ink chambers and are tapered into an end portion abutting the surface of the printhead 102. The guide walls 124, 125 are further mechanically supported by block portions e.g. 126 which are placed at regular intervals along the length of the ink supply unit. The block portions 126 have space at portions close to the back of printhead 102 for the flow of ink around the back surface thereof.

The ink supply unit is preferably formed from a multi-part plastic injection mold and the mold pieces e.g. 110, 111 (FIG. 13) snap together around the sponge pieces 107, 109. Subsequently, a syringe type device can be inserted in the ink refill holes and the ink reservoirs filled with ink with the air flowing out of the air outlets 113-115. Subsequently, the adhesive tape portion 117 and plug 121 are attached and the printhead tested for operation capabilities. Subsequently, the ink supply cartridge 42 can be readily removed for refilling by means of removing the ink supply cartridge, performing a washing cycle, and then utilizing the holes for the insertion of a refill syringe filled with ink for refilling the ink chamber before returning the ink supply cartridge 42 to a camera.

Turning now to FIG. 15, there is shown an example layout of the Image Capture and Processing Chip (ICP) 48.

The Image Capture and Processing Chip 48 provides most of the electronic functionality of the camera with the exception of the print head chip. The chip 48 is a highly integrated system. It combines CMOS image sensing, analog to digital conversion, digital image processing, DRAM storage, ROM, and miscellaneous control functions in a single chip.

The chip is estimated to be around 32 mm² using a leading edge 0.18 micron CMOS/DRAM/APS process. The chip size and cost can scale somewhat with Moore's law, but is dominated by a CMOS active pixel sensor array 201, so scaling is limited as the sensor pixels approach the diffraction limit.

The ICP 48 includes CMOS logic, a CMOS image sensor, DRAM, and analog circuitry. A very small amount of flash memory or other non-volatile memory is also preferably included for protection against reverse engineering.

Alternatively, the ICP can readily be divided into two chips: one for the CMOS imaging array, and the other for the remaining circuitry. The cost of this two chip solution should not be significantly different than the single chip ICP, as the extra cost of packaging and bond-pad area is somewhat cancelled by the reduced total wafer area requiring the color filter fabrication steps.

The ICP preferably contains the following functions:

Function 1.5 megapixel image sensor Analog Signal Processors Image sensor column decoders Image sensor row decoders Analogue to Digital Conversion (ADC) Column ADC's Auto exposure 12 Mbits of DRAM DRAM Address Generator Color interpolator Convolver Color ALU Halftone matrix ROM Digital halftoning Print head interface 8 bit CPU core Program ROM Flash memory Scratchpad SRAM Parallel interface (8 bit) Motor drive transistors (5) Clock PLL JTAG test interface Test circuits Busses Bond pads

The CPU, DRAM, Image sensor, ROM, Flash memory, Parallel interface, JTAG interface and ADC can be vendor supplied cores. The ICP is intended to run on 1.5V to minimize power consumption and allow convenient operation from two AA type battery cells.

FIG. 15 illustrates a layout of the ICP 48. The ICP 48 is dominated by the imaging array 201, which consumes around 80% of the chip area. The imaging array is a CMOS 4 transistor active pixel design with a resolution of 1,500×1,000. The array can be divided into the conventional configuration, with two green pixels, one red pixel, and one blue pixel in each pixel group. There are 750×500 pixel groups in the imaging array.

The latest advances in the field of image sensing and CMOS image sensing in particular can be found in the October, 1997 issue of IEEE Transactions on Electron Devices and, in particular, pages 1689 to 1968. Further, a specific implementation similar to that disclosed in the present application is disclosed in Wong et al., “CMOS Active Pixel Image Sensors Fabricated Using a 1.8V, 0.25 μm CMOS Technology”, IEDM 1996, page 915.

The imaging array uses a 4 transistor active pixel design of a standard configuration. To minimize chip area and therefore cost, the image sensor pixels should be as small as feasible with the technology available. With a four transistor cell, the typical pixel size scales as 20 times the lithographic feature size. This allows a minimum pixel area of around 3.6 μm×3.6 μm. However, the photosite must be substantially above the diffraction limit of the lens. It is also advantageous to have a square photosite, to maximize the margin over the diffraction limit in both horizontal and vertical directions. In this case, the photosite can be specified as 2.5 μm×2.5 μm. The photosite can be a photogate, pinned photodiode, charge modulation device, or other sensor.

The four transistors are packed as an ‘L’ shape, rather than a rectangular region, to allow both the pixel and the photosite to be square. This reduces the transistor packing density slightly, increasing pixel size. However, the advantage in avoiding the diffraction limit is greater than the small decrease in packing density.

The transistors also have a gate length which is longer than the minimum for the process technology. These have been increased from a drawn length of 0.18 micron to a drawn length of 0.36 micron. This is to improve the transistor matching by making the variations in gate length represent a smaller proportion of the total gate length.

The extra gate length, and the ‘L’ shaped packing, mean that the transistors use more area than the minimum for the technology. Normally, around 8 μm² would be required for rectangular packing. Preferably, 9.75 μm² has been allowed for the transistors.

The total area for each pixel is 16 μm², resulting from a pixel size of 4 μm×4 μm. With a resolution of 1,500×1,000, the area of the imaging array 101 is 6,000 μm×4,000 μm, or 24 mm².

The presence of a color image sensor on the chip affects the process required in two major ways:

-   -   The CMOS fabrication process should be optimised to minimize         dark current

Color filters are required. These can be fabricated using dyed photosensitive polyimides, resulting in an added process complexity of three spin coatings, three photolithographic steps, three development steps, and three hardbakes.

There are 15,000 analog signal processors (ASPs) 205, one for each of the columns of the sensor. The ASPs amplify the signal, provide a dark current reference, sample and hold the signal, and suppress the fixed pattern noise (FPN).

There are 375 analog to digital converters 206, one for each four columns of the sensor array. These may be delta-sigma or successive approximation type ADC's. A row of low column ADC's are used to reduce the conversion speed required, and the amount of analog signal degradation incurred before the signal is converted to digital. This also eliminates the hot spot (affecting local dark current) and the substrate coupled noise that would occur if a single high speed ADC was used. Each ADC also has two four bit DAC's which trim the offset and scale of the ADC to further reduce FPN variations between columns. These DAC's are controlled by data stored in flash memory during chip testing.

The column select logic 204 is a 1:1500 decoder which enables the appropriate digital output of the ADCs onto the output bus. As each ADC is shared by four columns, the least significant two bits of the row select control 4 input analog multiplexors.

A row decoder 207 is a 1:1000 decoder which enables the appropriate row of the active pixel sensor array. This selects which of the 1000 rows of the imaging array is connected to analog signal processors. As the rows are always accessed in sequence, the row select logic can be implemented as a shift register.

An auto exposure system 208 adjusts the reference voltage of the ADC 205 in response to the maximum intensity sensed during the previous frame period. Data from the green pixels is passed through a digital peak detector. The peak value of the image frame period before capture (the reference frame) is provided to a digital to analogue converter (DAC), which generates the global reference voltage for the column ADCs. The peak detector is reset at the beginning of the reference frame. The minimum and maximum values of the three RGB color components are also collected for color correction.

The second largest section of the chip is consumed by a DRAM 210 used to hold the image. To store the 1,500×1,000 image from the sensor without compression, 1.5 Mbytes of DRAM 210 are required. This equals 12 Mbits, or slightly less than 5% of a 256 Mbit DRAM. The DRAM technology assumed is of the 256 Mbit generation implemented using 0.18 μm CMOS.

Using a standard 8F cell, the area taken by the memory array is 3.11 mm². When row decoders, column sensors, redundancy, and other factors are taken into account, the DRAM requires around 4 mm².

This DRAM 210 can be mostly eliminated if analog storage of the image signal can be accurately maintained in the CMOS imaging array for the two seconds required to print the photo. However, digital storage of the image is preferable as it is maintained without degradation, is insensitive to noise, and allows copies of the photo to be printed considerably later.

A DRAM address generator 211 provides the write and read addresses to the DRAM 210. Under normal operation, the write address is determined by the order of the data read from the CMOS image sensor 201. This will typically be a simple raster format. However, the data can be read from the sensor 201 in any order, if matching write addresses to the DRAM are generated. The read order from the DRAM 210 will normally simply match the requirements of a color interpolator and the print head. As the cyan, magenta, and yellow rows of the print head are necessarily offset by a few pixels to allow space for nozzle actuators, the colors are not read from the DRAM simultaneously. However, there is plenty of time to read all of the data from the DRAM many times during the printing process. This capability is used to eliminate the need for FIFOs in the print head interface, thereby saving chip area. All three RGB image components can be read from the DRAM each time color data is required. This allows a color space converter to provide a more sophisticated conversion than a simple linear RGB to CMY conversion.

Also, to allow two dimensional filtering of the image data without requiring line buffers, data is re-read from the DRAM array.

The address generator may also implement image effects in certain models of camera. For example, passport photos are generated by a manipulation of the read addresses to the DRAM. Also, image framing effects (where the central image is reduced), image warps, and kaleidoscopic effects can all be generated by manipulating the read addresses of the DRAM.

While the address generator 211 may be implemented with substantial complexity if effects are built into the standard chip, the chip area required for the address generator is small, as it consists only of address counters and a moderate amount of random logic.

A color interpolator 214 converts the interleaved pattern of red, 2×green, and blue pixels into RGB pixels. It consists of three 8 bit adders and associated registers. The divisions are by either 2 (for green) or 4 (for red and blue) so they can be implemented as fixed shifts in the output connections of the adders.

A convolver 215 is provided as a sharpening filter which applies a small convolution kernel (5×5) to the red, green, and blue planes of the image. The convolution kernel for the green plane is different from that of the red and blue planes, as green has twice as many samples. The sharpening filter has five functions:

-   -   to improve the color interpolation from the linear interpolation         provided by the color interpolator, to a close approximation of         a sinc interpolation;     -   to compensate for the image ‘softening’ which occurs during         digitisation;     -   to adjust the image sharpness to match average consumer         preferences, which are typically for the image to be slightly         sharper than reality. As the single use camera is intended as a         consumer product, and not a professional photographic products,         the processing can match the most popular settings, rather than         the most accurate;     -   to suppress the sharpening of high frequency (individual pixel)         noise. The function is similar to the ‘unsharp mask’ process;         and     -   to antialias Image Warping.

These functions are all combined into a single convolution matrix. As the pixel rate is low (less than 1 Mpixel per second) the total number of multiplies required for the three color channels is 56 million multiplies per second. This can be provided by a single multiplier. Fifty bytes of coefficient ROM are also required.

A color ALU 113 combines the functions of color compensation and color space conversion into the one matrix multiplication, which is applied to every pixel of the frame. As with sharpening, the color correction should match the most popular settings, rather than the most accurate.

A color compensation circuit of the color ALU provides compensation for the lighting of the photo. The vast majority of photographs are substantially improved by a simple color compensation, which independently normalizes the contrast and brightness of the three color components.

A color look-up table (CLUT) 212 is provided for each color component. These are three separate 256×8 SRAMs, requiring a total of 6,144 bits. The CLUTs are used as part of the color correction process. They are also used for color special effects, such as stochastically selected “wild color” effects.

A color space conversion system of the color ALU converts from the RGB color space of the image sensor to the CMY color space of the printer. The simplest conversion is a 1's complement of the RGB data. However, this simple conversion assumes perfect linearity of both color spaces, and perfect dye spectra for both the color filters of the image sensor, and the ink dyes. At the other extreme is a tri-linear interpolation of a sampled three dimensional arbitrary transform table. This can effectively match any non-linearity or differences in either color space. Such a system is usually necessary to obtain good color space conversion when the print engine is a color electrophotographic

However, since the non-linearity of a halftoned ink jet output is very small, a simpler system can be used. A simple matrix multiply can provide excellent results. This requires nine multiplies and six additions per contone pixel. However, since the contone pixel rate is low (less than 1 Mpixel/sec) these operations can share a single multiplier and adder. The multiplier and adder are used in a color ALU which is shared with the color compensation function.

Digital halftoning can be performed as a dispersed dot ordered dither using a stochastic optimized dither cell. A halftone matrix ROM 216 is provided for storing dither cell coefficients. A dither cell size of 32=32 is adequate to ensure that the cell repeat cycle is not visible. The three colors—cyan, magenta, and yellow—are all dithered using the same cell, to ensure maximum co-positioning of the ink dots. This minimizes ‘muddying’ of the mid-tones which results from bleed of dyes from one dot to adjacent dots while still wet. The total ROM size required is 1 KByte, as the one ROM is shared by the halftoning units for each of the three colors.

The digital halftoning used is dispersed dot ordered dither with stochastic optimized dither matrix. While dithering does not produce an image quite as ‘sharp’ as error diffusion, it does produce a more accurate image with fewer artifacts. The image sharpening produced by error diffusion is artificial, and less controllable and accurate than ‘unsharp mask’ filtering performed in the contone domain. The high print resolution (1,600 dpi×1,600 dpi) results in excellent quality when using a well formed stochastic dither matrix.

Digital halftoning is performed by a digital halftoning unit 217 using a simple comparison between the contone information from the DRAM 210 and the contents of the dither matrix 216. During the halftone process, the resolution of the image is changed from the 250 dpi of the captured contone image to the 1,600 dpi of the printed image. Each contone pixel is converted to an average of 40.96 halftone dots.

The ICP incorporates a 16 bit microcontroller CPU core 219 to run the miscellaneous camera functions, such as reading the buttons, controlling the motor and solenoids, setting up the hardware, and authenticating the refill station. The processing power required by the CPU is very modest, and a wide variety of processor cores can be used. As the entire CPU program is run from a small ROM 220 program compatibility between camera versions is not important, as no external programs are run. A 2 Mbit (256 Kbyte) program and data ROM 220 is included on chip. Most of this ROM space is allocated to data for outline graphics and fonts for specialty cameras. The program requirements are minor. The single most complex task is the encrypted authentication of the refill station. The ROM requires a single transistor per bit.

A Flash memory 221 may be used to store a 128 bit authentication code. This provides higher security than storage of the authentication code in ROM, as reverse engineering can be made essentially impossible. The Flash memory is completely covered by third level metal, making the data impossible to extract using scanning probe microscopes or electron beams. The authentication code is stored in the chip when manufactured. At least two other Flash bits are required for the authentication process: a bit which locks out reprogramming of the authentication code, and a bit which indicates that the camera has been refilled by an authenticated refill station. The flash memory can also be used to store FPN correction data for the imaging array. Additionally, a phase locked loop rescaling parameter is stored for scaling the clocking cycle to an appropriate correct time. The clock frequency does not require crystal accuracy since no date functions are provided. To eliminate the cost of a crystal, an on chip oscillator with a phase locked loop 224 is used. As the frequency of an on-chip oscillator is highly variable from chip to chip, the frequency ratio of the oscillator to the PLL is digitally trimmed during initial testing. The value is stored in Flash memory 221. This allows the clock PLL to control the ink-jet heater pulse width with sufficient accuracy.

A scratchpad SRAM is a small static RAM 222 with a 6T cell. The scratchpad provided temporary memory for the 16 bit CPU. 1024 bytes is adequate.

A print head interface 223 formats the data correctly for the print head. The print head interface also provides all of the timing signals required by the print head. These timing signals may vary depending upon temperature, the number of dots printed simultaneously, the print medium in the print roll, and the dye density of the ink in the print roll.

The following is a table of external connections to the print head interface:

Connection Function Pins DataBits[0-7] Independent serial data to the eight 8 segments of the printhead BitClock Main data clock for the print head 1 ColorEnable[0-2] Independent enable signals for the 3 CMY actuators, allowing different pulse times for each color. BankEnable[0-1] Allows either simultaneous or 2 interleaved actuation of two banks of nozzles. This allows two different print speed/power consumption tradeoffs NozzleSelect[0-4] Selects one of 32 banks of nozzles 5 for simultaneous actuation ParallelXferClock Loads the parallel transfer register 1 with the data from the shift registers Total 20

The printhead utilized is composed of eight identical segments, each 1.25 cm long. There is no connection between the segments on the print head chip. Any connections required are made in the external TAB bonding film, which is double sided. The division into eight identical segments is to simplify lithography using wafer steppers. The segment width of 1.25 cm fits easily into a stepper field. As the printhead chip is long and narrow (10 cm×0.3 mm), the stepper field contains a single segment of 32 print head chips. The stepper field is therefore 1.25 cm×1.6 cm. An average of four complete print heads are patterned in each wafer step.

A single BitClock output line connects to all 8 segments on the printhead. The 8 DataBits lines lead one to each segment, and are clocked into the 8 segments on the print head simultaneously (on a BitClock pulse). For example, dot 0 is transferred to segment₀, dot 750 is transferred to segment₁, dot 1500 to segment₂ etc simultaneously.

The ParallelXferClock is connected to each of the 8 segments on the printhead, so that on a single pulse, all segments transfer their bits at the same time.

The NozzleSelect, BankEnable and ColorEnable lines are connected to each of the 8 segments, allowing the print head interface to independently control the duration of the cyan, magenta, and yellow nozzle energizing pulses. Registers in the Print Head Interface allow the accurate specification of the pulse duration between 0 and 6 ms, with a typical duration of 2 ms to 3 ms.

A parallel interface 125 connects the ICP to individual static electrical signals. The CPU is able to control each of these connections as memory mapped I/O via a low speed bus.

The following is a table of connections to the parallel interface:

Connection Direction Pins Paper transport stepper motor Output 4 Capping solenoid Output 1 Copy LED Output 1 Photo button Input 1 Copy button Input 1 Total 8

Seven high current drive transistors e.g. 227 are required. Four are for the four phases of the main stepper motor two are for the guillotine motor, and the remaining transistor is to drive the capping solenoid. These transistors are allocated 20,000 square microns (600,000 F) each. As the transistors are driving highly inductive loads, they must either be turned off slowly, or be provided with a high level of back EMF protection. If adequate back EMF protection cannot be provided using the chip process chosen, then external discrete transistors should be used. The transistors are never driven at the same time as the image sensor is used. This is to avoid voltage fluctuations and hot spots affecting the image quality. Further, the transistors are located as far away from the sensor as possible.

A standard JTAG (Joint Test Action Group) interface 228 is included in the ICP for testing purposes and for interrogation by the refill station. Due to the complexity of the chip, a variety of testing techniques are required, including BIST (Built In Self Test) and functional block isolation. An overhead of 10% in chip area is assumed for chip testing circuitry for the random logic portions. The overhead for the large arrays the image sensor and the DRAM is smaller.

The JTAG interface is also used for authentication of the refill station. This is included to ensure that the cameras are only refilled with quality paper and ink at a properly constructed refill station, thus preventing inferior quality refills from occurring. The camera must authenticate the refill station, rather than vice versa. The secure protocol is communicated to the refill station during the automated test procedure. Contact is made to four gold plated spots on the ICP/print head TAB by the refill station as the new ink is injected into the print head.

FIG. 16 illustrates a rear view of the next step in the construction process whilst FIG. 17 illustrates a front view.

Turning now to FIG. 16, the assembly of the camera system proceeds via first assembling the ink supply mechanism 40. The flex PCB is interconnected with batteries 84, only one of which is shown, which are inserted in the middle portion of a print roll 85 which is wrapped around a plastic former 86. An end cap 89 is provided at the other end of the print roll 85 so as to fasten the print roll and batteries firmly to the ink supply mechanism.

The solenoid coil is interconnected (not shown) to interconnects 97, 98 (FIG. 8) which include leaf spring ends for interconnection with electrical contacts on the Flex PCB so as to provide for electrical control of the solenoid.

Turning now to FIGS. 17-19 the next step in the construction process is the insertion of the relevant gear trains into the side of the camera chassis. FIG. 17 illustrates a front view, FIG. 18 illustrates a rear view and FIG. 19 also illustrates a rear view. The first gear train comprising gear wheels 22, 23 is utilized for driving the guillotine blade with the gear wheel 23 engaging the gear wheel 65 of FIG. 8. The second gear train comprising gear wheels 24, 25 and 26 engage one end of the print roller 61 of FIG. 8. As best indicated in FIG. 18, the gear wheels mate with corresponding pins on the surface of the chassis with the gear wheel 26 being snap fitted into corresponding mating hole 27.

Next, as illustrated in FIG. 20, the assembled platten unit 60 is then inserted between the print roll 85 and aluminum cutting blade 43.

Turning now to FIG. 21, by way of illumination, there is illustrated the electrically interactive components of the camera system. As noted previously, the components are based around a Flex PCB board and include a TAB film 58 which interconnects the printhead 102 with the image sensor and processing chip 48. Power is supplied by two AA type batteries 83, 84 and a paper drive stepper motor 16 is provided in addition to a rotary guillotine motor 17.

An optical element 31 is provided for snapping into a top portion of the chassis 12. The optical element 31 includes portions defining an optical view finder 32, 33 which are slotted into mating portions 35, 36 in view finder channel 37. Also provided in the optical element 31 is a lensing system 38 for magnification of the prints left number in addition to an optical pipe element 39 for piping light from the LED 5 for external display.

Turning next to FIG. 22, the assembled unit 90 is then inserted into a front outer case 91 which includes button 4 for activation of printouts.

Turning now to FIG. 23, next, the unit 90 is provided with a snap-on back cover 93 which includes a slot 6 and copy print button 7. A wrapper label containing instructions and advertising (not shown) is then wrapped around the outer surface of the camera system and pinch clamped to the cover by means of clamp strip 96 which can comprise a flexible plastic or rubber strip.

Subsequently, the preferred embodiment is ready for use as a one time use camera system that provides for instant output images on demand. It will be evident that the preferred embodiment further provides for a refillable camera system. A used camera can be collected and its outer plastic cases removed and recycled. A new paper roll and batteries can be added and the ink cartridge refilled. A series of automatic test routines can then be carried out to ensure that the printer is properly operational. Further, in order to ensure only authorized refills are conducted so as to enhance quality, routines in the on-chip program ROM can be executed such that the camera authenticates the refilling station using a secure protocol. Upon authentication, the camera can reset an internal paper count and an external case can be fitted on the camera system with a new outer label. Subsequent packing and shipping can then take place.

It will be further readily evident to those skilled in the art that the program ROM can be modified so as to allow for a variety of digital processing routines. In addition to the digitally enhanced photographs optimized for mainstream consumer preferences, various other models can readily be provided through mere re-programming of the program ROM. For example, a sepia classic old fashion style output can be provided through a remapping of the color mapping function. A further alternative is to provide for black and white outputs again through a suitable color remapping algorithm. Minimum color can also be provided to add a touch of color to black and white prints to produce the effect that was traditionally used to colorize black and white photos. Further, passport photo output can be provided through suitable address remappings within the address generators. Further, edge filters can be utilized as is known in the field of image processing to produce sketched art styles. Further, classic wedding borders and designs can be placed around an output image in addition to the provision of relevant clip arts. For example, a wedding style camera might be provided. Further, a panoramic mode can be provided so as to output the well known panoramic format of images. Further, a postcard style output can be provided through the printing of postcards including postage on the back of a print roll surface. Further, cliparts can be provided for special events such as Halloween, Christmas etc. Further, kaleidoscopic effects can be provided through address remappings and wild color effects can be provided through remapping of the color lookup table. Many other forms of special event cameras can be provided for example, cameras dedicated to the Olympics, movie tie-ins, advertising and other special events.

The operational mode of the camera can be programmed so that upon the depressing of the take photo a first image is sampled by the sensor array to determine irrelevant parameters. Next a second image is again captured which is utilized for the output. The captured image is then manipulated in accordance with any special requirements before being initially output on the paper roll. The LED light is then activated for a predetermined time during which the DRAM is refreshed so as to retain the image. If the print copy button is depressed during this predetermined time interval, a further copy of the photo is output. After the predetermined time interval where no use of the camera has occurred, the onboard CPU shuts down all power to the camera system until such time as the take button is again activated. In this way, substantial power savings can be realized.

Ink Jet Technologies

The embodiments of the invention use an ink jet printer type device. Of course many different devices could be used. However presently popular ink jet printing technologies are unlikely to be suitable.

The most significant problem with thermal inkjet is power consumption. This is approximately 100 times that required for high speed, and stems from the energy-inefficient means of drop ejection. This involves the rapid boiling of water to produce a vapor bubble which expels the ink. Water has a very high heat capacity, and must be superheated in thermal inkjet applications. This leads to an efficiency of around 0.02%, from electricity input to drop momentum (and increased surface area) out.

The most significant problem with piezoelectric inkjet is size and cost. Piezoelectric crystals have a very small deflection at reasonable drive voltages, and therefore require a large area for each nozzle. Also, each piezoelectric actuator must be connected to its drive circuit on a separate substrate. This is not a significant problem at the current limit of around 300 nozzles per print head, but is a major impediment to the fabrication of pagewidth print heads with 19,200 nozzles.

Ideally, the inkjet technologies used meet the stringent requirements of in-camera digital color printing and other high quality, high speed, low cost printing applications. To meet the requirements of digital photography, new inkjet technologies have been created.

The target features include:

low power (less than 10 Watts)

high resolution capability (1,600 dpi or more)

photographic quality output

low manufacturing cost

small size (pagewidth times minimum cross section)

high speed (<2 seconds per page).

All of these features can be met or exceeded by the inkjet systems described below with differing levels of difficulty, forty-five different inkjet technologies have been developed by the Assignee to give a wide range of choices for high volume manufacture. These technologies form part of separate applications assigned to the present Assignee as set out in the table below.

The inkjet designs shown here are suitable for a wide range of digital printing systems, from battery powered one-time use digital cameras, through to desktop and network printers, and through to commercial printing systems For ease of manufacture using standard process equipment, the printhead is designed to be a monolithic 0.5 micron CMOS chip with MEMS post processing. For color photographic applications, the print head is 100 mm long, with a width which depends upon the inkjet type. The smallest print head designed is IJ38, which is 0.35 mm wide, giving a chip area of 35 square mm. The print heads each contain 19,200 nozzles plus data and control circuitry.

Ink is supplied to the back of the print head by injection molded plastic ink channels. The molding requires 50 micron features, which can be created using a lithographically micromachined insert in a standard injection molding tool. Ink flows through holes etched through the wafer to the nozzle chambers fabricated on the front surface of the wafer. The print head is connected to the camera circuitry by tape automated bonding.

Cross-Referenced Applications

The following table is a guide to cross-referenced patent applications filed concurrently herewith and discussed hereinafter with the reference being utilized in subsequent tables when referring to a particular case:

Docket No. Reference Title IJ01US IJ01 Radiant Plunger Ink Jet Printer IJ02US IJ02 Electrostatic Ink Jet Printer IJ03US IJ03 Planar Thermoelastic Bend Actuator Ink Jet IJ04US IJ04 Stacked Electrostatic Ink Jet Printer IJ05US IJ05 Reverse Spring Lever Ink Jet Printer IJ06US IJ06 Paddle Type Ink Jet Printer IJ07US IJ07 Permanent Magnet Electromagnetic Ink Jet Printer IJ08US IJ08 Planar Swing Grill Electromagnetic Ink Jet Printer IJ09US IJ09 Pump Action Refill Ink Jet Printer IJ10US IJ10 Pulsed Magnetic Field Ink Jet Printer IJ11US IJ11 Two Plate Reverse Firing Electromagnetic Ink Jet Printer IJ12US IJ12 Linear Stepper Actuator Ink Jet Printer IJ13US IJ13 Gear Driven Shutter Ink Jet Printer IJ14US IJ14 Tapered Magnetic Pole Electromagnetic Ink Jet Printer IJ15US IJ15 Linear Spring Electromagnetic Grill Ink Jet Printer IJ16US IJ16 Lorenz Diaphragm Electromagnetic Ink Jet Printer IJ17US IJ17 PTFE Surface Shooting Shuttered Oscillating Pressure Ink Jet Printer IJ18US IJ18 Buckle Grip Oscillating Pressure Ink Jet Printer IJ19US IJ19 Shutter Based Ink Jet Printer IJ20US IJ20 Curling Calyx Thermoelastic Ink Jet Printer IJ21US IJ21 Thermal Actuated Ink Jet Printer IJ22US IJ22 Iris Motion Ink Jet Printer IJ23US IJ23 Direct Firing Thermal Bend Actuator Ink Jet Printer IJ24US IJ24 Conductive PTFE Ben Activator Vented Ink Jet Printer IJ25US IJ25 Magnetostrictive Ink Jet Printer IJ26US IJ26 Shape Memory Alloy Ink Jet Printer IJ27US IJ27 Buckle Plate Ink Jet Printer IJ28US IJ28 Thermal Elastic Rotary Impeller Ink Jet Printer IJ29US IJ29 Thermoelastic Bend Actuator Ink Jet Printer IJ30US IJ30 Thermoelastic Bend Actuator Using PTFE and Corrugated Copper Ink Jet Printer IJ31US IJ31 Bend Actuator Direct Ink Supply Ink Jet Printer IJ32US IJ32 A High Young's Modulus Thermoelastic Ink Jet Printer IJ33US IJ33 Thermally actuated slotted chamber wall ink jet printer IJ34US IJ34 Ink Jet Printer having a thermal actuator comprising an external coiled spring IJ35US IJ35 Trough Container Ink Jet Printer IJ36US IJ36 Dual Chamber Single Vertical Actuator Ink Jet IJ37US IJ37 Dual Nozzle Single Horizontal Fulcrum Actuator Ink Jet IJ38US IJ38 Dual Nozzle Single Horizontal Actuator Ink Jet IJ39US IJ39 A single bend actuator cupped paddle ink jet printing device IJ40US IJ40 A thermally actuated ink jet printer having a series of thermal actuator units IJ41US IJ41 A thermally actuated ink jet printer including a tapered heater element IJ42US IJ42 Radial Back-Curling Thermoelastic Ink Jet IJ43US IJ43 Inverted Radial Back-Curling Thermoelastic Ink Jet IJ44US IJ44 Surface bend actuator vented ink supply ink jet printer IJ45US IJ45 Coil Acutuated Magnetic Plate Ink Jet Printer Tables of Drop-on-Demand Inkjets

Eleven important characteristics of the fundamental operation of individual inkjet nozzles have been identified. These characteristics are largely orthogonal, and so can be elucidated as an eleven dimensional matrix. Most of the eleven axes of this matrix include entries developed by the present assignee.

The following tables form the axes of an eleven dimensional table of inkjet types.

Actuator mechanism (18 types)

Basic operation mode (7 types)

Auxiliary mechanism (8 types)

Actuator amplification or modification method (17 types)

Actuator motion (19 types)

Nozzle refill method (4 types)

Method of restricting back-flow through inlet (10 types)

Nozzle clearing method (9 types)

Nozzle plate construction (9 types)

Drop ejection direction (5 types)

Ink type (7 types)

The complete eleven dimensional table represented by these axes contains 36.9 billion possible configurations of inkjet nozzle. While not all of the possible combinations result in a viable inkjet technology, many million configurations are viable. It is clearly impractical to elucidate all of the possible configurations. Instead, certain inkjet types have been investigated in detail. These are designated IJ01 to IJ45 above.

Other inkjet configurations can readily be derived from these forty-five examples by substituting alternative configurations along one or more of the eleven axes. Most of the IJ01 to IJ45 examples can be made into inkjet print heads with characteristics superior to any currently available inkjet technology.

Where there are prior art examples known to the inventor, one or more of these examples are listed in the examples column of the tables below. The IJ01 to IJ45 series are also listed in the examples column. In some cases, a printer may be listed more than once in a table, where it shares characteristics with more than one entry.

Suitable applications include: Home printers, Office network printers, Short run digital printers, Commercial print systems, Fabric printers, Pocket printers, Internet WWW printers, Video printers, Medical imaging, Wide format printers, Notebook PC printers, Fax machines, Industrial printing systems, Photocopiers, Photographic minilabs etc.

The information associated with the aforementioned eleven dimensional matrix are set out in the following tables.

ACTUATOR MECHANISM (APPLIED ONLY TO SELECTED INK DROPS) Actuator Mechanism Description Advantages Disadvantages Examples Thermal bubble An electrothermal heater Large force generated High power Canon Bubblejet 1979 heats the ink to Simple construction Ink carrier limited Endo et al GB patent above boiling point, No moving parts to water 2,007,162 transferring significant Fast operation Low efficiency Xerox heater-in-pit 1990 heat to the aqueous ink. Small chip area required for High temperatures Hawkins et al U.S. Pat. No. A bubble nucleates and actuator required 4,899,181 quickly forms, expelling High mechanical Hewlett-Packard TIJ the ink. The efficiency stress 1982 Vaught et al of the process is low, Unusual materials U.S. Pat. No. 4,490,728 with typically less than required 0.05% of the electrical Large drive energy being transformed transistors into kinetic energy of Cavitation causes the drop. actuator failure Kogation reduces bubble formation Large print heads are difficult to fabricate Piezoelectric A piezoelectric Low power consumption Very large area Kyser et al U.S. Pat. No. crystal such as lead Many ink types can be used required for 3,946,398 lanthanum zirconate Fast operation actuator Zoltan U.S. Pat. No. 3,683,212 (PZT) is electrically High efficiency Difficult to 1973 Stemme U.S. Pat. No. activated, and either integrate with 3,747,120 expands, shears, or electronics Epson Stylus bends to apply pressure High voltage drive Tektronix to the ink, ejecting transistors required IJ04 drops. Full pagewidth print heads impractical due to actuator size Requires electrical poling in high field strengths during manufacture Electro-strictive An electric field is Low power consumption Low maximum strain Seiko Epson, Usui et all used to activate Many ink types can be used (approx. 0.01%) JP 253401/96 electrostriction in Low thermal expansion Large area required IJ04 relaxor materials such Electric field strength required for actuator due to as lead lanthanum (approx. 3.5 V/μm) can be low strain zirconate titanate generated without difficulty Response speed is (PLZT) or lead Does not require electrical marginal (~10 μs) magnesium niobate poling High voltage drive (PMN). transistors required Full pagewidth print heads impractical due to actuator size Ferroelectric An electric field is Low power consumption Difficult to IJ04 used to induce a Many ink types can be used integrate with phase transition Fast operation (<1 μs) electronics between the Relatively high longitudinal Unusual materials antiferroelectric strain such as PLZSnT are (AFE) and ferroelectric High efficiency required (FE) phase. Perovskite Electric field strength of around Actuators require materials such as 3 V/μm can be readily a large area tin modified lead provided lanthanum zirconate titanate (PLZSnT) exhibit large strains of up to 1% associated with the AFE to FE phase transition. Electrostatic Conductive plates are Low power consumption Difficult to operate IJ02, IJ04 plates separated by a Many ink types can be used electrostatic devices compressible or fluid Fast operation in an aqueous dielectric (usually environment air). Upon application The electrostatic of a voltage, the actuator will normally plates attract each need to be separated other and displace ink, from the ink causing drop ejection. Very large area The conductive plates required to achieve may be in a comb or high forces honeycomb structure, or High voltage drive stacked to increase the transistors may be surface area and required therefore the force. Full pagewidth print heads are not competitive due to actuator size Electrostatic pull A strong electric field Low current consumption High voltage required 1989 Saito et al, U.S. Pat. No. on ink is applied to the Low temperature May be damaged by 4,799,068 ink, whereupon sparks due to air 1989 Miura et al, U.S. Pat. No. electrostatic attraction breakdown 4,810,954 accelerates the ink Required field Tone-jet towards the print strength increases medium. as the drop size decreases High voltage drive transistors required Electrostatic field attracts dust Permanent An electromagnet Low power consumption Complex fabrication IJ07, IJ10 magnet electro- directly attracts a Many ink types can be used Permanent magnetic magnetic permanent magnet, Fast operation material such as displacing ink and High efficiency Neodymium Iron Boron causing drop ejection. Easy extension from single (NdFeB) required. Rare earth magnets nozzles to pagewidth print High local currents with a field strength heads required around 1 Tesla can be Copper metalization used. Examples are: should be used for Samarium Cobalt long electromigration (SaCo) and magnetic lifetime and low materials in the resistivity neodymium iron boron Pigmented inks are family (NdFeB, usually infeasible NdDyFeBNb, NdDyFeB, etc) Operating temperature limited to the Curie temperature (around 540 K) Soft magnetic core A solenoid induced a Low power consumption Complex fabrication IJ01, IJ05, IJ08, IJ10 electro-magnetic magnetic field in a Many ink types can be used Materials not usually IJ12, IJ14, IJ15, IJ17 soft magnetic core or Fast operation present in a CMOS fab yoke fabricated from a High efficiency such as NiFe, CoNiFe, ferrous material such as Easy extension from single or CoFe are electroplated iron nozzles to pagewidth print required alloys such as CoNiFe heads High local currents [1], CoFe, or NiFe required alloys. Typically, the Copper metalization soft magnetic material should be used for is in two parts, long electromigration which are normally held lifetime and low apart by a spring. When resistivity the solenoid is actuated, Electroplating is the two parts attract, required displacing the ink. High saturation flux density is required (2.0-2.1 T is achievable with CoNiFe [1]) Magnetic The Lorenz force acting Low power consumption Force acts as a IJ06, IJ11, IJ13, IJ16 Lorenz force on a current carrying Many ink types can be used twisting motion wire in a magnetic field Fast operation Typically, only a is utilized. High efficiency quarter of the sole- This allows the Easy extension from single noid length provides magnetic field to be nozzles to pagewidth print force in a useful supplied externally to heads direction the print head, for High local currents example with rare earth required permanent magnets. Copper metalization Only the current should be used for carrying wire need be long electromigration fabricated on the print- lifetime and low head, simplifying resistivity materials requirements. Pigmented inks are usually infeasible Magneto-striction The actuator uses the Many ink types can be used Force acts as a Fischenbeck, U.S. Pat. No. giant magnetostrictive Fast operation twisting motion 4,032,929 effect of materials such Easy extension from single Unusual materials IJ25 as Terfenol-D (an nozzles to pagewidth print such as Terfenol-D alloy of terbium, heads are required dysprosium and iron High force is available High local currents developed at the required Naval Ordnance Copper metalization Laboratory, hence Ter- should be used for Fe-NOL). For best long electromigration efficiency, the lifetime and low actuator should be resistivity pre-stressed to Pre-stressing may approx. 8 MPa. be required Surface tension Ink under positive Low power consumption Requires supplementary Silverbrook, EP 0771 reduction pressure is held in Simple construction force to effect drop 658 A2 and related a nozzle by surface No unusual materials required separation patent applications tension. The surface in fabrication Requires special ink tension of the ink is High efficiency surfactants reduced below the Easy extension from single Speed may be limited bubble threshold, nozzles to pagewidth print by surfactant causing the ink to heads properties egress from the nozzle. Viscosity The ink viscosity is Simple construction Requires supplementary Silverbrook, EP 0771 reduction locally reduced to No unusual materials required force to effect drop 658 A2 and related select which drops in fabrication separation patent applications are to be ejected. A Easy extension from single Requires special ink viscosity reduction nozzles to pagewidth print viscosity properties can be achieved heads High speed is electrothermally with difficult to achieve most inks, but Requires oscillating special inks can be ink pressure engineered for a 100:1 A high temperature viscosity reduction. difference (typically 80 degrees) is required Acoustic An acoustic wave is Can operate without a nozzle Complex drive circuitry 1993 Hadimioglu et al, generated and plate Complex fabrication EUP 550,192 focussed upon the Low efficiency 1993 Elrod et al, EUP drop ejection region. Poor control of drop 572,220 position Poor control of drop volume Thermoelastic An actuator which Low power consumption Efficient aqueous IJ03, IJ09, IJ17, IJ18 bend actuator relies upon Many ink types can be used operation requires IJ19, IJ20, IJ21, IJ22 differential thermal Simple planar fabrication a thermal insulator IJ23, IJ24, IJ27, IJ28 expansion upon Small chip area required for on the hot side IJ29, IJ30, IJ31, IJ32 Joule heating is used. each actuator Corrosion prevention IJ33, IJ34, IJ35, IJ36 Fast operation can be difficult IJ37, IJ38, IJ39, IJ40 High efficiency Pigmented inks may IJ41 CMOS compatible voltages and be infeasible, as currents pigment particles Standard MEMS processes can may jam the bend be used actuator Easy extension from single nozzles to pagewidth print heads High CTE A material with a very High force can be generated Requires special IJ09, IJ17, IJ18, IJ20 thermoelastic high coefficient of PTFE is a candidate for low material (e.g. PTFE) IJ21, IJ22, IJ23, IJ24 actuator thermal expansion (CTE) dielectric constant insulation Requires a PTFE IJ27, IJ28, IJ29, IJ30 such as in ULSI deposition process, IJ31, IJ42, IJ43, IJ44 polytetrafluoroethylene Very low power consumption which is not yet (PTFE) is used. Many ink types can be used standard in ULSI fabs As high CTE materials Simple planar fabrication PTFE deposition are usually non- Small chip area required for cannot be followed conductive, a heater each actuator with high temperature fabricated from a Fast operation (above 350 °C.) conductive material High efficiency processing is incorporated. A 50 CMOS compatible voltages and Pigmented inks may μm long PTFE bend currents be infeasible, as actuator with Easy extension from single pigment particles polysilicon heater nozzles to pagewidth print may jam the bend and 15 mW power heads actuator input can provide 180 μN force and 10 μm deflection. Actuator motions include: Bend Push Buckle Rotate Conductive A polymer with a High force can be generated Requires special IJ24 polymer high coefficient of Very low power consumption materials development thermoelastic thermal expansion Many ink types can be used (High CTE conductive actuator (such as PTFE) is Simple planar fabrication polymer) doped with conducting Small chip area required for Requires a PTFE substances to each actuator deposition process, increase its Fast operation which is not yet conductivity to about High efficiency standard in ULSI fabs 3 orders of magnitude CMOS compatible voltages and PTFE deposition cannot below that of currents be followed with high copper. The conducting Easy extension from single temperature (above polymer expands nozzles to pagewidth print 350 °C.) processing when resistively heated. heads Evaporation and CVD Examples of conducting deposition techniques dopants include: cannot be used Carbon nanotubes Pigmented inks may Metal fibers be infeasible, as Conductive polymers pigment particles such as doped may jam the bend polythiophene actuator Carbon granules Shape memory A shape memory alloy High force is available (stresses Fatigue limits IJ26 alloy such as TiNi (also of hundreds of MPa) maximum number of known as Nitinol - Large strain is available (more cycles Nickel Titanium alloy than 3%) Low strain (1%) is developed at the High corrosion resistance required to extend Naval Ordnance Simple construction fatigue resistance Laboratory) is Easy extension from single Cycle rate limited thermally switched nozzles to pagewidth print by heat removal between its weak heads Requires unusual martensitic state and Low voltage operation materials (TiNi) its high stiffness The latent heat of austenic state. The transformation must shape of the actuator be provided in its martensitic High current operation state is deformed Requires pre-stressing relative to the to distort the austenic shape. martensitic state The shape change causes ejection of a drop. Linear Magnetic Linear magnetic Linear Magnetic actuators can Requires unusual semi- IJ12 Actuator actuators include the be constructed with high conductor materials Linear Induction thrust, long travel, and high such as soft magnetic Actuator (LIA), Linear efficiency using planar alloys (e.g. CoNiFe Permanent Magnet semiconductor fabrication [1]) Synchronous Actuator techniques Some varieties also (LPMSA), Linear Long actuator travel is available require permanent Reluctance Synchronous Medium force is available magnetic materials Actuator (LRSA), Linear Low voltage operation such as Neodymium Switched Reluctance iron boron (NdFeB) Actuator (LSRA), Requires complex and the Linear Stepper multi-phase drive Actuator (LSA). circuitry High current operation

BASIC OPERATION MODE Operational mode Description Advantages Disadvantages Examples Actuator directly This is the simplest Simple operation Drop repetition rate is usually limited to less Thermal inkjet pushes ink mode of operation: No external fields required than 10 KHz. However, this is not Piezoelectric inkjet the actuator directly Satellite drops can be avoided if fundamental to the method, but is related IJ01, IJ02, IJ03, IJ04 supplies sufficient drop velocity is less than 4 to the refill method normally used IJ05, IJ06, IJ07, IJ09 kinetic energy to m/s All of the drop kinetic energy must be IJ11, IJ12, IJ14, IJ16 expel the drop. The Can be efficient, depending provided by the actuator IJ20, IJ22, IJ23, IJ24 drop must have a upon the actuator used Satellite drops usually form if drop velocity IJ25, IJ26, IJ27, IJ28 sufficient velocity is greater than 4.5 m/s IJ29, IJ30, IJ31, IJ32 to overcome the IJ33, IJ34, IJ35, IJ36 surface tension. IJ37, IJ38, IJ39, IJ40 IJ41, IJ42, IJ43, IJ44 Proximity The drops to be Very simple print head Requires close proximity between the print Silverbrook, EP 0771 printed are selected fabrication can be used head and the print media or transfer roller 658 A2 and related by some manner (e.g. The drop selection means does May require two print heads printing patent applications thermally induced not need to provide the alternate rows of the image surface tension energy required to separate Monolithic color print heads are difficult reduction of pressur- the drop from the nozzle ized ink). Selected drops are separated from the ink in the nozzle by contact with the print medium or a transfer roller. Electrostatic pull The drops to be printed Very simple print head Requires very high electrostatic field Silverbrook, EP 0771 on ink are selected by fabrication can be used Electrostatic field for small nozzle sizes is 658 A2 and related some manner (e.g. The drop selection means does above air breakdown patent applications thermally induced not need to provide the Electrostatic field may attract dust Tone-Jet surface tension energy required to separate reduction of pressur- the drop from the nozzle ized ink). Selected drops are separated from the ink in the nozzle by a strong electric field. Magnetic pull on The drops to be Very simple print head Requires magnetic ink Silverbrook, EP 0771 ink printed are selected fabrication can be used Ink colors other than black are difficult 658 A2 and related by some manner (e.g. The drop selection means does Requires very high magnetic fields patent applications thermally induced not need to provide the surface tension energy required to separate reduction of pressur- the drop from the nozzle ized ink). Selected drops are separated from the ink in the nozzle by a strong magnetic field acting on the magnetic ink. Shutter The actuator moves a High speed (>50 KHz) Moving parts are required IJ13, IJ17, IJ21 shutter to block ink operation can be achieved Requires ink pressure modulator flow to the nozzle. due to reduced refill time Friction and wear must be considered The ink pressure is Drop timing can be very Stiction is possible pulsed at a multiple accurate of the drop ejection The actuator energy can be frequency. very low Shuttered grill The actuator moves a Actuators with small travel can Moving parts are required IJ08, IJ15, IJ18, IJ19 shutter to block ink be used Requires ink pressure modulator flow through a grill Actuators with small force can Friction and wear must be considered to the nozzle. The be used Stiction is possible shutter movement need High speed (>50 KHz) only be equal to operation can be achieved the width of the grill holes. Pulsed magnetic A pulsed magnetic Extremely low energy operation Requires an external pulsed magnetic field IJ10 pull on ink pusher field attracts an ‘ink is possible Requires special materials for both the pusher’ at the drop No heat dissipation problems actuator and the ink pusher ejection frequency. Complex construction An actuator controls a catch, which prevents the ink pusher from moving when a drop is not to be ejected.

AUXILIARY MECHANISM (APPLIED TO ALL NOZZLES) Auxiliary Mechanism Description Advantages Disadvantages Examples None The actuator directly Simplicity of construction Drop ejection energy must be supplied Most inkjets, including fires the ink drop, Simplicity of operation by individual nozzle actuator piezoelectric and and there is no Small physical size thermal bubble. external field or other IJ01-IJ07, IJ09, IJ11 mechanism required. IJ12, IJ14, IJ20, IJ22 IJ23-IJ45 Oscillating ink The ink pressure Oscillating ink pressure can Requires external ink pressure oscillator Silverbrook, EP 0771 pressure oscillates, providing provide a refill pulse, Ink pressure phase and amplitude must 658 A2 and related (including much of the drop allowing higher operating be carefully controlled patent applications acoustic ejection energy. The speed Acoustic reflections in the ink chamber IJ08, IJ13, IJ15, IJ17 stimulation) actuator selects The actuators may operate with must be designed for IJ18, IJ19, IJ21 which drops are to be much lower energy fired by selectively Acoustic lenses can be used to blocking or enabling focus the sound on the nozzles. The ink nozzles pressure oscillation may be achieved by vibrating the print head, or preferably by an actuator in the ink supply. Media proximity The print head is Low power Precision assembly required Silverbrook, EP 0771 placed in close High accuracy Paper fibers may cause problems 658 A2 and related proximity to the Simple print head construction Cannot print on rough substrates patent applications print medium. Selected drops protrude from the print head further than unselected drops, and contact the print medium. The drop soaks into the medium fast enough to cause drop separation. Transfer roller Drops are printed to High accuracy Bulky Silverbrook, EP 0771 a transfer roller Wide range of print substrates Expensive 658 A2 and related instead of straight can be used Complex construction patent applications to the print medium. Ink can be dried on the transfer Tektronix hot melt A transfer roller roller piezoelectric inkjet can also be used for Any of the IJ series proximity drop separation. Electrostatic An electric field is Low power Field strength required for separation Silverbrook, EP 0771 used to accelerate Simple print head construction of small drops is near or above air 658 A2 and related selected drops towards breakdown patent applications the print medium. Tone-Jet Direct magnetic A magnetic field is Low power Requires magnetic ink Silverbrook, EP 0771 field used to accelerate Simple print head construction Requires strong magnetic field 658 A2 and related selected drops of patent applications magnetic ink towards the print medium. Cross magnetic The print head is Does not require magnetic Requires external magnet IJ06, IJ16 field placed in a constant materials to be integrated in Current densities may be high, resulting magnetic field. The the print head manufacturing in electromigration problems Lorenz force in a process current carrying wire is used to move the actuator. Pulsed magnetic A pulsed magnetic Very low power operation is Complex print head construction IJ10 field field is used to possible Magnetic materials required in print head cyclically attract a Small print head size paddle, which pushes on the ink. A small actuator moves a catch, which selectively prevents the paddle from moving.

ACTUATOR AMPLIFICATION OR MODIFICATION METHOD Actuator amplification Description Advantages Disadvantages Examples None No actuator mechanical Operational simplicity Many actuator mechanisms have insuf- Thermal Bubble InkJet amplification is ficient travel, or insufficient force, IJ01, IJ02, IJ06, IJ07 used. The actuator to efficiently drive the drop ejection IJ16, IJ25, IJ26 directly drives the process drop ejection process. Differential An actuator material Provides greater travel in a High stresses are involved Piezoelectric expansion bend expands more on reduced print head area Care must be taken that the materials IJ03, IJ09, IJ17-IJ24 actuator one side than on The bend actuator converts a do not delaminate IJ27 IJ29-IJ39, IJ42, the other. The high force low travel actuator Residual bend resulting from high IJ43, IJ44 expansion may be mechanism to high travel, temperature or high stress during thermal, piezoelectric, lower force mechanism. formation magnetostrictive, or other mechanism. Transient bend A trilayer bend Very good temperature stability High stresses are involved IJ40, IJ41 actuator actuator where the two High speed, as a new drop can Care must be taken that the materials outside layers are be fired before heat dissipates do not delaminate identical. This cancels Cancels residual stress of bend due to ambient formation temperature and residual stress. The actuator only responds to transient heating of one side or the other. Actuator stack A series of thin Increased travel Increased fabrication complexity Some piezoelectric ink actuators are stacked. Reduced drive voltage Increased possibility of short circuits jets This can be due to pinholes IJ04 appropriate where actuators require high electric field strength, such as electrostatic and piezoelectric actuators. Multiple actuators Multiple smaller Increases the force available Actuator forces may not add linearly, IJ12, IJ13, IJ18, IJ20 actuators are used from an actuator reducing efficiency IJ22, IJ28, IJ42, IJ43 simultaneously to Multiple actuators can be move the ink. Each positioned to control ink flow actuator need accurately provide only a portion of the force required. Linear Spring A linear spring is Matches low travel actuator Requires print head area for the spring IJ15 used to transform a with higher travel motion with small requirements travel and high force Non-contact method of motion into a longer travel, transformation lower force motion. Reverse spring The actuator loads a Better coupling to the ink Fabrication complexity IJ05, IJ11 spring. When the High stress in the spring actuator is turned off, the spring releases. This can reverse the force/distance curve of the actuator to make it compatible with the force/time requirements of the drop ejection. Coiled actuator A bend actuator is Increases travel Generally restricted to planar IJ17, IJ21, IJ34, IJ35 coiled to provide Reduces chip area implementations due to extreme greater travel in a Planar implementations are fabrication difficulty in other reduced chip area. relatively easy to fabricate. orientations. Flexure bend A bend actuator has Simple means of increasing Care must be taken not to exceed the IJ10, IJ19, IJ33 actuator a small region near travel of a bend actuator elastic limit in the flexure area the fixture point, Stress distribution is very uneven which flexes much Difficult to accurately model with finite more readily than element analysis the remainder of the actuator. The actuator flexing is effectively converted from an even coiling to an angular bend, resulting in greater travel of the actuator tip. Gears Gears can be used to Low force, low travel actuators Moving parts are required IJ13 increase travel at can be used Several actuator cycles are required the expense of Can be fabricated using More complex drive electronics duration. Circular standard surface MEMS Complex construction gears, rack and pinion, processes Friction, friction, and wear are possible ratchets, and other gearing methods can be used. Catch The actuator controls Very low actuator energy Complex construction IJ10 a small catch. The Very small actuator size Requires external force catch either enables Unsuitable for pigmented inks or disables movement of an ink pusher that is controlled in a bulk manner. Buckle plate A buckle plate can be Very fast movement achievable Must stay within elastic limits of the S. Hirata et al, “An Ink- used to change a materials for long device life jet Head . . . ”, Proc. slow actuator into a High stresses involved IEEE MEMS, February fast motion. It can Generally high power requirement 1996, pp 418-423. also convert a high IJ18, IJ27 force, low travel actuator into a high travel, medium force motion. Tapered magnetic A tapered magnetic Linearizes the magnetic Complex construction IJ14 pole pole can increase force/distance curve travel at the expense of force. Lever A lever and fulcrum Matches low travel actuator High stress around the fulcrum IJ32, IJ36, IJ37 is used to transform with higher travel a motion with small requirements travel and high force Fulcrum area has no linear into a motion with movement, and can be used longer travel and for a fluid seal lower force. The lever can also reverse the direction of travel. Rotary impeller The actuator is High mechanical advantage Complex construction IJ28 connected to a rotary The ratio of force to travel of Unsuitable for pigmented inks impeller. A small the actuator can be matched angular deflection of to the nozzle requirements by the actuator results varying the number of in a rotation of the impeller vanes impeller vanes, which push the ink against stationary vanes and out of the nozzle. Acoustic lens A refractive or No moving parts Large area required 1993 Hadimioglu et al, diffractive (e.g. zone Only relevant for acoustic ink jets EUP 550,192 plate) acoustic lens 1993 Elrod et al, EUP is used to concentrate 572,220 sound waves. Sharp conductive A sharp point is used Simple construction Difficult to fabricate using standard Tone-jet point to concentrate an VLSI processes for a surface ejecting electrostatic field. ink-jet Only relevant for electrostatic ink jets

ACTUATOR MOTION Actuator motion Description Advantages Disadvantages Examples Volume The volume of the Simple construction High energy is typically required to Hewlett-Packard expansion actuator changes, in the case achieve volume expansion. This leads to Thermal InkJet pushing the ink in of thermal ink jet thermal stress, cavitation, and kogation Canon Bubblejet all directions. in thermal ink jet implementations Linear, The actuator moves in Efficient coupling High fabrication complexity may be IJ01, IJ02, IJ04, IJ07 normal to a direction normal to ink drops required to achieve perpendicular motion IJ11, IJ14 chip surface to the print head ejected normal to surface. The nozzle the surface is typically in the line of movement. Linear, The actuator moves Suitable for planar Fabrication complexity IJ12, IJ13, IJ15, IJ33, parallel to parallel to the print fabrication Friction IJ34, IJ35, IJ36 chip surface head surface. Drop Stiction ejection may still be normal to the surface. Membrane push An actuator with a The effective Fabrication complexity 1982 Howkins U.S. Pat. No. high force but small area of the Actuator size 4,459,601 area is used to push actuator becomes Difficulty of integration in a VLSI a stiff membrane that the membrane area process is in contact with the ink. Rotary The actuator causes Rotary levers may Device complexity IJ05, IJ08, IJ13, IJ28 the rotation of some be used to May have friction at a pivot point element, such a grill increase travel or impeller Small chip area requirements Bend The actuator bends A very small Requires the actuator to be made from 1970 Kyser et al U.S. Pat. No. when energized. This change in at least two distinct layers, or to 3,946,398 may be due to dimensions can have a thermal difference across the 1973 Stemme U.S. Pat. No. differential thermal be converted actuator 3,747,120 expansion, piezo- to a large IJ03, IJ09, IJ10, IJ19 electric expansion, motion. IJ23, IJ24, IJ25, IJ29 magnetostriction, IJ30, IJ31, IJ33, IJ34 or other form of IJ35 relative dimensional change. Swivel The actuator swivels Allows operation Inefficient coupling to the ink motion IJ06 around a central where the net pivot. This motion is linear force on suitable where there the paddle is are opposite forces zero applied to opposite Small chip area sides of the paddle, requirements e.g. Lorenz force. Straighten The actuator is Can be used Requires careful balance of stresses to IJ26, IJ32 normally bent, and with shape ensure that the quiescent bend is straightens when memory alloys accurate energized. where the austenic phase is planar Double bend The actuator bends in One actuator can Difficult to make the drops ejected by IJ36, IJ37, IJ38 one direction when one be used to power both bend directions identical. element is energized, two nozzles. A small efficiency loss compared to and bends the other way Reduced chip size. equivalent single bend actuators. when another element is Not sensitive to energized. ambient temperature Shear Energizing the actuator Can increase the Not readily applicable to other actuator 1985 Fishbeck U.S. Pat. No. causes a shear motion in effective travel mechanisms 4,584,590 the actuator material. of piezoelectric actuators Radial The actuator squeezes Relatively easy High force required 1970 Zoltan U.S. Pat. No. constriction an ink reservoir, to fabricate Inefficient 3,683,212 forcing ink from a single nozzles Difficult to integrate with VLSI constricted nozzle. from glass processes tubing as macroscopic structures Coil/uncoil A coiled actuator Easy to fabricate Difficult to fabricate for non-planar IJ17, IJ21, IJ34, IJ35 uncoils or coils more as a planar devices tightly. The motion of VLSI process Poor out-of-plane stiffness the free end of the Small area actuator ejects the ink. required, therefore low cost Bow The actuator bows (or Can increase the Maximum travel is constrained IJ16, IJ18, IJ27 buckles) in the speed of travel High force required middle when energized. Mechanically rigid Push-Pull Two actuators control The structure is Not readily suitable for inkjets which IJ18 a shutter. One pinned at both directly push the ink actuator pulls the ends, so has a shutter, and the other high out-of- pushes it. plane rigidity Curl inwards A set of actuators curl Good fluid flow Design complexity IJ20, IJ42 inwards to reduce to the region the volume of ink that behind the they enclose. actuator increases efficiency Curl outwards A set of actuators Relatively simple Relatively large chip area IJ43 curl outwards, construction pressurizing ink in a chamber surrounding the actuators, and expelling ink from a nozzle in the chamber. Iris Multiple vanes enclose High efficiency High fabrication complexity IJ22 a volume of ink. These Small chip area Not suitable for pigmented inks simultaneously rotate, reducing the volume between the vanes. Acoustic vibration The actuator vibrates The actuator can Large area required for efficient 1993 Hadimioglu et al, at a high frequency. be physically operation at useful frequencies EUP 550,192 distant from the Acoustic coupling and crosstalk 1993 Elrod et al, EUP ink Complex drive circuitry 572,220 Poor control of drop volume and position None In various ink jet No moving parts Various other tradeoffs are required Silverbrook, EP 0771 designs the actuator to eliminate moving parts 658 A2 and related does not move. patent applications Tone-jet

NOZZLE REFILL METHOD Nozzle refill method Description Advantages Disadvantages Examples Surface tension After the actuator Fabrication simplicity Low speed Thermal inkjet is energized, it Operational simplicity Surface tension force relatively small Piezoelectric inkjet typically returns compared to actuator force IJ01-IJ07, IJ10-IJ14 rapidly to its normal Long refill time usually dominates the IJ16, IJ20, IJ22-IJ45 position. This rapid total repetition rate return sucks in air through the nozzle opening. The ink surface tension at the nozzle then exerts a small force restoring the meniscus to a minimum area. Shuttered Ink to the nozzle High speed Requires common ink pressure oscillator IJ08, IJ13, IJ15, IJ17 oscillating ink chamber is provided Low actuator energy, as the May not be suitable for pigmented inks IJ18, IJ19, IJ21 pressure at a pressure that actuator need only open or oscillates at twice close the shutter, instead of the drop ejection ejecting the ink drop frequency. When a drop is to be ejected, the shutter is opened for 3 half cycles: drop ejection, actuator return, and refill. Refill actuator After the main actuator High speed, as the nozzle is Requires two independent actuators per IJ09 has ejected a drop a actively refilled nozzle second (refill) actuator is energized. The refill actuator pushes ink into the nozzle chamber. The refill actuator returns slowly, to prevent its return from emptying the chamber again. Positive ink The ink is held a slight High refill rate, therefore a Surface spill must be prevented Silverbrook, EP 0771 pressure positive pressure. After high drop repetition rate is Highly hydrophobic print head surfaces 658 A2 and related the ink drop is ejected, possible are required patent applications the nozzle chamber fills Alternative for: quickly as surface IJ01-IJ07, IJ10-IJ14 tension and ink pressure IJ16, IJ20, IJ22-IJ45 both operate to refill the nozzle.

METHOD OF RESTRICTING BACK-FLOW THROUGH INLET Inlet back-flow restriction method Description Advantages Disadvantages Examples Long inlet The ink inlet channel Design simplicity Restricts refill rate Thermal inkjet channel to the nozzle chamber Operational simplicity May result in a relatively large chip Piezoelectric inkjet is made long and Reduces crosstalk area IJ42, IJ43 relatively narrow, Only partially effective relying on viscous drag to reduce inlet back-flow. Positive ink The ink is under a Drop selection and separation Requires a method (such as a nozzle rim Silverbrook, EP 0771 pressure positive pressure, forces can be reduced or effective hydrophobizing, or both) to 658 A2 and related so that in the Fast refill time prevent flooding of the ejection surface patent applications quiescent state some of the print head. Possible operation of the of the ink drop already following: protrudes from the IJ01-IJ07, IJ09-IJ12 nozzle. This reduces IJ14, IJ16, IJ20, IJ22, the pressure in the IJ23-IJ34, IJ36-IJ41 nozzle chamber which IJ44 is required to eject a certain volume of ink. The reduction in chamber pressure results in a reduction in ink pushed out through the inlet. Baffle One or more baffles The refill rate is not as Design complexity HP Thermal Ink Jet are placed in the restricted as the long May increase fabrication complexity Tektronix piezoelectric inlet ink flow. When inlet method. (e.g. Tektronix hot melt Piezoelectric inkjet the actuator is Reduces crosstalk print heads). energized, the rapid ink movement creates eddies which restrict the flow through the inlet. The slower refill process is unre- stricted, and does not result in eddies. Flexible flap In this method Significantly reduces back-flow Not applicable to most inkjet config- Canon restricts inlet recently disclosed by for edge-shooter thermal ink urations Canon, the expanding jet devices Increased fabrication complexity actuator (bubble) Inelastic deformation of polymer flap pushes on a flexible results in creep over extended use flap that restricts the inlet. Inlet filter A filter is located Additional advantage of ink Restricts refill rate IJ04, IJ12, IJ24, IJ27 between the ink inlet filtration May result in complex construction IJ29, IJ30 and the nozzle chamber. Ink filter may be fabricated The filter has a with no additional process multitude of small steps holes or slots, restricting ink flow. The filter also removes particles which may block the nozzle. Small inlet The ink inlet channel Design simplicity Restricts refill rate IJ02, IJ37, IJ44 compared to to the nozzle chamber May result in a relatively large chip nozzle has a substantially area smaller cross section Only partially effective than that of the nozzle, resulting in easier ink egress out of the nozzle than out of the inlet. Inlet shutter A secondary actuator Increases speed of the ink- Requires separate refill actuator and IJ09 controls the position jet print head operation drive circuit of a shutter, closing off the ink inlet when the main actuator is energized. The inlet is The method avoids Back-flow problem is Requires careful design to minimize the IJ01, IJ03, IJ05, IJ06 located behind the problem of inlet eliminated negative pressure behind the paddle IJ07, IJ10, IJ11, IJ14 the ink-pushing back-flow by arrang- IJ16, IJ22, IJ23, IJ25 surface ing the ink-pushing IJ28, IJ31, IJ32, IJ33 surface of the IJ34, IJ35, IJ36, IJ39 actuator between the IJ40, IJ41 inlet and the nozzle. Part of the The actuator and a Significant reductions in back- Small increase in fabrication complexity IJ07, IJ20, IJ26, IJ38 actuator moves wall of the ink flow can be achieved to shut off chamber are arranged Compact designs possible the inlet so that the motion of the actuator closes off the inlet. Nozzle actuator In some configura- Ink back-flow problem is None related to ink back-flow on Silverbrook, EP 0771 does not result tions of ink jet, eliminated actuation 658 A2 and related in ink back-flow there is no expan- patent applications sion or movement of Valve-jet an actuator which may Tone-jet cause ink back-flow IJ08, IJ13, IJ15, IJ17 through the inlet. IJ18, IJ19, IJ21

NOZZLE CLEARING METHOD Nozzle Clearing method Description Advantages Disadvantages Examples Normal nozzle All of the nozzles are No added complexity on the May not be sufficient to displace dried Most ink jet systems firing fired periodically, print head ink IJ01-IJ07, IJ09-IJ12 before the ink has a IJ14, IJ16, IJ20, IJ22 chance to dry. When IJ23-IJ34, IJ36-IJ45 not in use the nozzles are sealed (capped) against air. The nozzle firing is usually performed during a special clear- ing cycle, after first moving the print head to a cleaning station. Extra power to In systems which heat Can be highly effective if the Requires higher drive voltage for Silverbrook, EP 0771 ink heater the ink, but do not heater is adjacent to the clearing 658 A2 and related boil it under normal nozzle May require larger drive transistors patent applications situations, nozzle clearing can be achieved by over- powering the heater and boiling ink at the nozzle. Rapid succession The actuator is fired Does not require extra drive Effectiveness depends substantially May be used with: of actuator pulses in rapid succession. circuits on the print head upon the configuration of the inkjet IJ01-IJ07, IJ09-IJ11 In some configurations, Can be readily controlled and nozzle IJ14, IJ16, IJ20, IJ22 this may cause heat initiated by digital logic IJ23-IJ25, IJ27-IJ34 build-up at the nozzle IJ36-IJ45 which boils the ink, clearing the nozzle. In other situations, it may cause sufficient vibrations to dislodge clogged nozzles. Extra power to Where an actuator is A simple solution where Not suitable where there is a hard limit May be used with: ink pushing not normally driven applicable to actuator movement IJ03, IJ09, IJ16, IJ20 actuator to the limit of its IJ23, IJ24, IJ25, IJ27 motion, nozzle clearing IJ29, IJ30, IJ31, IJ32 may be assisted by IJ39, IJ40, IJ41, IJ42 providing an enhanced IJ43, IJ44, IJ45 drive signal to the actuator. Acoustic An ultrasonic wave is A high nozzle clearing High implementation cost if system does IJ08, IJ13, IJ15, IJ17 resonance applied to the ink capability can be achieved not already include an acoustic actuator IJ18, IJ19, IJ21 chamber. This wave is May be implemented at very of an appropriate low cost in systems which amplitude and fre- already include acoustic quency to cause actuators sufficient force at the nozzle to clear blockages. This is easiest to achieve if the ultrasonic wave is at a resonant frequency of the ink cavity. Nozzle clearing A microfabricated plate Can clear severely clogged Accurate mechanical alignment is re- Silverbrook, EP 0771 plate is pushed against the nozzles quired 658 A2 and related nozzles. The plate has Moving parts are required patent applications a post for every nozzle. There is risk of damage to the nozzles The array of posts Accurate fabrication is required Ink pressure pulse The pressure of the May be effective where other Requires pressure pump or other May be used with all IJ ink is temporarily methods cannot be used pressure actuator series ink jets increased so that ink Expensive streams from all of Wasteful of ink the nozzles. This may be used in con- junction with actuator energizing. Print head wiper A flexible ‘blade’ Effective for planar print head Difficult to use if print head surface is Many ink jet systems is wiped across the surfaces non-planar or very fragile print head surface. Low cost Requires mechanical parts The blade is usually Blade can wear out in high volume print fabricated from a systems flexible polymer, e.g. rubber or synthetic elastomer. Separate ink A separate heater is Can be effective where other Fabrication complexity Can be used with many boiling heater provided at the nozzle clearing methods IJ series ink jets nozzle although the cannot be used normal drop e-ection Can be implemented at no mechanism does not additional cost in some inkjet require it. The configurations heaters do not require individual drive circuits, as many nozzles can be cleared simultaneously, and no imaging is required.

NOZZLE PLATE CONSTRUCTION Nozzle plate construction Description Advantages Disadvantages Examples Electroformed A nozzle plate is Fabrication simplicity High temperatures and pressures are Hewlett Packard nickel separately fabricated required to bond nozzle plate Thermal Inkjet from electroformed Minimum thickness constraints nickel, and bonded Differential thermal expansion to the print head chip. Laser ablated or Individual nozzle holes No masks required Each hole must be individually formed Canon Bubblejet drilled polymer are ablated by an Can be quite fast Special equipment required 1988 Sercel et al., intense UV laser in a Some control over nozzle Slow where there are many thousands SPIE, Vol. 998 Excimer nozzle plate, which profile is possible of nozzles per print head Beam Applications, is typically a polymer Equipment required is May produce thin burrs at exit holes pp. 76-83 such as polyimide or relatively low cost 1993 Watanabe et al., polysulphone U.S. Pat. No. 5,208,604 Silicon micro- A separate nozzle High accuracy is attainable Two part construction K. Bean, IEEE machined plate is micromachined High cost Transactions on from single crystal Requires precision alignment Electron Devices, Vol. silicon, and bonded Nozzles may be clogged by adhesive ED-25, No. 10, 1978, to the print head pp 1185-1195 wafer. Xerox 1990 Hawkins et al., U.S. Pat. No. 4,899,181 Glass Fine glass capillaries No expensive equipment Very small nozzle sizes are difficult to 1970 Zoltan U.S. capillaries are drawn from glass required form Pat. No. 3,683,212 tubing. This method Simple to make single nozzles Not suited for mass production has been used for making individual nozzles, but is difficult to use for bulk manufacturing of print heads with thousands of nozzles. Monolithic, The nozzle plate is High accuracy (<1 μm) Requires sacrificial layer under the Silverbrook, EP 0771 surface micro- deposited as a layer Monolithic nozzle plate to form the nozzle chamber 658 A2 and related machined using using standard VLSI Low cost Surface may be fragile to the touch patent applications VLSI litho- deposition techniques. Existing processes can be IJ01, IJ02, IJ04, IJ11 graphic Nozzles are etched in used IJ12, IJ17, IJ18, IJ20 processes the nozzle plate using IJ22, IJ24, IJ27, IJ28 VLSI lithography and IJ29, IJ30, IJ31, IJ32 etching. IJ33, IJ34, IJ36, IJ37 IJ38, IJ39, IJ40, IJ41 IJ42, IJ43, IJ44 Monolithic, The nozzle plate is a High accuracy (<1 μm) Requires long etch times IJ03, IJ05, IJ06, IJ07 etched through buried etch stop in Monolithic Requires a support wafer IJ08, IJ09, IJ10, IJ13 substrate the wafer. Nozzle Low cost IJ14, IJ15, IJ16, IJ19 chambers are etched in No differential expansion IJ21, IJ23, IJ25, IJ26 the front of the wafer, and the wafer is thinned from the back side. Nozzles are then etched in the etch stop layer. No nozzle plate Various methods have No nozzles to become clogged Difficult to control drop position accu- Ricoh 1995 Sekiya et al been tried to eliminate rately U.S. Pat. No. 5,412,413 the nozzles entirely, Crosstalk problems 1993 Hadimioglu et al to prevent nozzle EUP 550,192 clogging. These include 1993 Elrod et al EUP thermal bubble mecha- 572,220 nisms and acoustic lens mechanisms Trough Each drop ejector has Reduced manufacturing Drop firing direction is sensitive to IJ35 a trough through complexity wicking. which a paddle moves. Monolithic There is no nozzle plate. Nozzle slit The elimination of No nozzles to become clogged Difficult to control drop position accu- 1989 Saito et al instead of nozzle holes and rately U.S. Pat. No. individual replacement by a Crosstalk problems 4,799,068 nozzles slit encompassing many actuator posi- tions reduces nozzle clogging, but in- creases crosstalk due to ink surface waves

DROP EJECTION DIRECTION Ejection direction Description Advantages Disadvantages Examples Edge Ink flow is along the Simple construction Nozzles limited to edge Canon Bubblejet 1979 (‘edge shooter’) surface of the chip, No silicon etching required High resolution is difficult Endo et al GB patent and ink drops are Good heat sinking via sub- Fast color printing requires one print 2,007,162 ejected from the chip strate head per color Xerox heater-in-pit 1990 edge. Mechanically strong Hawkins et al U.S. Ease of chip handing Pat. No. 4,899,181 Tone-jet Surface Ink flow is along the No bulk silicon etching Maximum ink flow is severely restricted Hewlett-Packard TIJ (‘roof shooter’) surface of the chip, required 1982 Vaught et al and ink drops are Silicon can make an effective U.S. Pat. No. ejected from the chip heat sink 4,490,728 surface, normal to Mechanical strength IJ02, IJ11, IJ12, IJ20 the plane of the chip. IJ22 Through chip, Ink flow is through High ink flow Requires bulk silicon etching Silverbrook, EP 0771 forward the chip, and ink Suitable for pagewidth print 658 A2 and related (‘up shooter’) drops are ejected High nozzle packing density patent applications from the front sur- therefore low manufacturing IJ04, IJ17, IJ18, IJ24 face of the chip. cost IJ27-IJ45 Through chip, Ink flow is through High ink flow Requires wafer thinning IJ01, IJ03, IJ05, IJ06 reverse the chip, and ink Suitable for pagewidth print Requires special handling during IJ07, IJ08, IJ09, IJ10 (‘down shooter’) drops are ejected High nozzle packing density manufacture IJ13, IJ14, IJ15, IJ16 from the rear surface therefore low manufacturing IJ19, IJ21, IJ23, IJ25 of the chip. cost IJ26 Through actuator Ink flow is through Suitable for piezoelectric Pagewidth print heads require several Epson Stylus the actuator, which print heads thousand connections to drive circuits Tektronix hot melt is not fabricated as Cannot be manufactured in standard piezoelectric ink jets part of the same CMOS fabs substrate as the Complex assembly required drive transistors.

INK TYPE Ink type Description Advantages Disadvantages Examples Aqueous, dye Water based ink Environmentally friendly Slow drying Most existing inkjets which typically No odor Corrosive All IJ series ink jets contains: water, Bleeds on paper Silverbrook, EP 0771 dye, surfactant, May strikethrough 658 A2 and related humectant, and Cockles paper patent applications biocide. Modern ink dyes have high water- fastness, light fastness Aqueous, pigment Water based ink Environmentally friendly Slow drying IJ02, IJ04, IJ21, IJ26 which typically No odor Corrosive IJ27, IJ30 contains: water, Reduced bleed Pigment may clog nozzles Silverbrook, EP 0771 pigment, surfactant, Reduced wicking Pigment may clog actuator mechanisms 658 A2 and related humectant, and Reduced strikethrough Cockles paper patent applications biocide. Piezoelectric ink-jets Pigments have an Thermal ink jets (with advantage in reduced significant bleed, wicking restrictions) and strikethrough. Methyl Ethyl MEK is a highly vola- Very fast drying Odorous All IJ series ink jets Ketone (MEK) tile solvent used for Prints on various substrates Flammable industrial printing such as metals and plastics on difficult surfaces such as aluminum cans. Alcohol Alcohol based inks Fast drying Slight odor All IJ series ink jets (ethanol, 2- can be used where Operates at sub-freezing Flammable butanol, and the printer must temperatures others) operate at tempera- Reduced paper cockle tures below the Low cost freezing point of water. An example of this is in-camera consumer photographic printing. Phase change The ink is solid at No drying time - ink instantly High viscosity Tektronix hot melt (hot melt) room temperature, and freezes on the print medium Printed ink typically has a ‘waxy’ feel piezoelectric ink jets is melted in the Almost any print medium can Printed pages may ‘block’ 1989 Nowak U.S. Pat. print head before jet- be used Ink temperature may be above the curie No. 4,820,346 ting. Hot melt inks No paper cockle occurs point of permanent magnets All IJ series ink jets are usually wax based, No wicking occurs Ink heaters consume power with a melting point No bleed occurs Long warm-up time around 80° C. After No strikethrough occurs jetting the ink freezes almost instantly upon contacting the print medium or a transfer roller. Oil Oil based inks are High solubility medium for High viscosity: this is a significant All IJ series ink jets extensively used in some dyes limitation for use in inkjets, which offset printing. They Does not cockle paper usually require a low viscosity. Some have advantages in Does not wick through paper short chain and multi-branched oils improved characteris- have a sufficiently low viscosity. tics on paper (especi- Slow drying ally no wicking or cockle). Oil soluble dies and pigments are required. Microemulsion A microemulsion is a Stops ink bleed Viscosity higher than water All IJ series ink jets stable, self forming High dye solubility Cost is slightly higher than water based emulsion of oil, water, Water, oil, and amphiphilic ink and surfactant. The soluble dies can be used High surfactant concentration required characteristic drop Can stabilize pigment (around 5%) size is less than suspensions 100 nm, and is deter- mined by the preferred curvature of the surfactant. Ink Jet Printing

A large number of new forms of ink jet printers have been developed to facilitate alternative ink jet technologies for the image processing and data distribution system. Various combinations of ink jet devices can be included in printer devices incorporated as part of the present invention. Australian Provisional Patent Applications relating to these ink jets which are specifically incorporated by cross reference include:

Australian Provisional Number Filing Date Title PO8066 15 Jul. 1997 Image Creation Method and Apparatus (IJ01) PO8072 15 Jul. 1997 Image Creation Method and Apparatus (IJ02) PO8040 15 Jul. 1997 Image Creation Method and Apparatus (IJ03) PO8071 15 Jul. 1997 Image Creation Method and Apparatus (IJ04) PO8047 15 Jul. 1997 Image Creation Method and Apparatus (IJ05) PO8035 15 Jul. 1997 Image Creation Method and Apparatus (IJ06) PO8044 15 Jul. 1997 Image Creation Method and Apparatus (IJ07) PO8063 15 Jul. 1997 Image Creation Method and Apparatus (IJ08) PO8057 15 Jul. 1997 Image Creation Method and Apparatus (IJ09) PO8056 15 Jul. 1997 Image Creation Method and Apparatus (IJ10) PO8069 15 Jul. 1997 Image Creation Method and Apparatus (IJ11) PO8049 15 Jul. 1997 Image Creation Method and Apparatus (IJ12) PO8036 15 Jul. 1997 Image Creation Method and Apparatus (IJ13) PO8048 15 Jul. 1997 Image Creation Method and Apparatus (IJ14) PO8070 15 Jul. 1997 Image Creation Method and Apparatus (IJ15) PO8067 15 Jul. 1997 Image Creation Method and Apparatus (IJ16) PO8001 15 Jul. 1997 Image Creation Method and Apparatus (IJ17) PO8038 15 Jul. 1997 Image Creation Method and Apparatus (IJ18) PO8033 15 Jul. 1997 Image Creation Method and Apparatus (IJ19) PO8002 15 Jul. 1997 Image Creation Method and Apparatus (IJ20) PO8068 15 Jul. 1997 Image Creation Method and Apparatus (IJ21) PO8062 15 Jul. 1997 Image Creation Method and Apparatus (IJ22) PO8034 15 Jul. 1997 Image Creation Method and Apparatus (IJ23) PO8039 15 Jul. 1997 Image Creation Method and Apparatus (IJ24) PO8041 15 Jul. 1997 Image Creation Method and Apparatus (IJ25) PO8004 15 Jul. 1997 Image Creation Method and Apparatus (IJ26) PO8037 15 Jul. 1997 Image Creation Method and Apparatus (IJ27) PO8043 15 Jul. 1997 Image Creation Method and Apparatus (IJ28) PO8042 15 Jul. 1997 Image Creation Method and Apparatus (IJ29) PO8064 15 Jul. 1997 Image Creation Method and Apparatus (IJ30) PO9389 23 Sep. 1997 Image Creation Method and Apparatus (IJ31) PO9391 23 Sep. 1997 Image Creation Method and Apparatus (IJ32) PP0888 12 Dec. 1997 Image Creation Method and Apparatus (IJ33) PP0891 12 Dec. 1997 Image Creation Method and Apparatus (IJ34) PP0890 12 Dec. 1997 Image Creation Method and Apparatus (IJ35) PP0873 12 Dec. 1997 Image Creation Method and Apparatus (IJ36) PP0993 12 Dec. 1997 Image Creation Method and Apparatus (IJ37) PP0890 12 Dec. 1997 Image Creation Method and Apparatus (IJ38) PP1398 19 Jan. 1998 An Image Creation Method and Apparatus (IJ39) PP2592 25 Mar. 1998 An Image Creation Method and Apparatus (IJ40) PP2593 25 Mar. 1998 Image Creation Method and Apparatus (IJ41) PP3991 9 Jun. 1998 Image Creation Method and Apparatus (IJ42) PP3987 9 Jun. 1998 Image Creation Method and Apparatus (IJ43) PP3985 9 Jun. 1998 Image Creation Method and Apparatus (IJ44) PP3983 9 Jun. 1998 Image Creation Method and Apparatus (IJ45) Ink Jet Manufacturing

Further, the present application may utilize advanced semiconductor fabrication techniques in the construction of large arrays of ink jet printers. Suitable manufacturing techniques are described in the following Australian provisional patent specifications incorporated here by cross-reference:

Australian Provisional Number Filing Date Title PO7935 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM01) PO7936 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM02) PO7937 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM03) PO8061 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM04) PO8054 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM05) PO8065 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM06) PO8055 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM07) PO8053 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM08) PO8078 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM09) PO7933 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM10) PO7950 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM11) PO7949 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM12) PO8060 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM13) PO8059 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM14) PO8073 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM15) PO8076 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM16) PO8075 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM17) PO8079 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM18) PO8050 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM19) PO8052 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM20) PO7948 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM21) PO7951 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM22) PO8074 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM23) PO7941 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM24) PO8077 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM25) PO8058 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM26) PO8051 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM27) PO8045 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM28) PO7952 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM29) PO8046 15 Jul. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM30) PO8503 11 Aug. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM30a) PO9390 23 Sep. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM31) PO9392 23 Sep. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM32) PP0889 12 Dec. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM35) PP0887 12 Dec. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM36) PP0882 12 Dec. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM37) PP0874 12 Dec. 1997 A Method of Manufacture of an Image Creation Apparatus (IJM38) PP1396 19 Jan. 1998 A Method of Manufacture of an Image Creation Apparatus (IJM39) PP2591 25 Mar. 1998 A Method of Manufacture of an Image Creation Apparatus (IJM41) PP3989 9 Jun. 1998 A Method of Manufacture of an Image Creation Apparatus (IJM40) PP3990 9 Jun. 1998 A Method of Manufacture of an Image Creation Apparatus (IJM42) PP3986 9 Jun. 1998 A Method of Manufacture of an Image Creation Apparatus (IJM43) PP3984 9 Jun. 1998 A Method of Manufacture of an Image Creation Apparatus (IJM44) PP3982 9 Jun. 1998 A Method of Manufacture of an Image Creation Apparatus (IJM45) Fluid Supply

Further, the present application may utilize an ink delivery system to the ink jet head. Delivery systems relating to the supply of ink to a series of ink jet nozzles are described in the following Australian provisional patent specifications, the disclosure of which are hereby incorporated by cross-reference:

Australian Provisional Number Filing Date Title PO8003 15 Jul. 1997 Supply Method and Apparatus (F1) PO8005 15 Jul. 1997 Supply Method and Apparatus (F2) PO9404 23 Sep. 1997 A Device and Method (F3) MEMS Technology

Further, the present application may utilize advanced semiconductor microelectromechanical techniques in the construction of large arrays of ink jet printers. Suitable microelectromechanical techniques are described in the following Australian provisional patent specifications incorporated here by cross-reference:

Australian Provisional Number Filing Date Title PO7943 15 Jul. 1997 A device (MEMS01) PO8006 15 Jul. 1997 A device (MEMS02) PO8007 15 Jul. 1997 A device (MEMS03) PO8008 15 Jul. 1997 A device (MEMS04) PO8010 15 Jul. 1997 A device (MEMS05) PO8011 15 Jul. 1997 A device (MEMS06) PO7947 15 Jul. 1997 A device (MEMS07) PO7945 15 Jul. 1997 A device (MEMS08) PO7944 15 Jul. 1997 A device (MEMS09) PO7946 15 Jul. 1997 A device (MEMS10) PO9393 23 Sep. 1997 A Device and Method (MEMS11) PP0875 12 Dec. 1997 A device (MEMS12) PP0894 12 Dec. 1997 A Device and Method (MEMS13) IR Technologies

Further, the present application may include the utilization of a disposable camera system such as those described in the following Australian provisional patent specifications incorporated here by cross-reference:

Australian Provisional Number Filing Date Title PP0895 12 Dec. 1997 An Image Creation Method and Apparatus (IR01) PP0870 12 Dec. 1997 A Device and Method (IR02) PP0869 12 Dec. 1997 A Device and Method (IR04) PP0887 12 Dec. 1997 Image Creation Method and Apparatus (IR05) PP0885 12 Dec. 1997 An Image Production System (IR06) PP0884 12 Dec. 1997 Image Creation Method and Apparatus (IR10) PP0886 12 Dec. 1997 Image Creation Method and Apparatus (IR12) PP0871 12 Dec. 1997 A Device and Method (IR13) PP0876 12 Dec. 1997 An Image Processing Method and Apparatus (IR14) PP0877 12 Dec. 1997 A Device and Method (IR16) PP0878 12 Dec. 1997 A Device and Method (IR17) PP0879 12 Dec. 1997 A Device and Method (IR18) PP0883 12 Dec. 1997 A Device and Method (IR19) PP0880 12 Dec. 1997 A Device and Method (IR20) PP0881 12 Dec. 1997 A Device and Method (IR21) DotCard Technologies

Further, the present application may include the utilization of a data distribution system such as that described in the following Australian provisional patent specifications incorporated here by cross-reference:

Australian Provisional Number Filing Date Title PP2370 16 Mar. 1998 Data Processing Method and Apparatus (Dot01) PP2371 16 Mar. 1998 Data Processing Method and Apparatus (Dot02) Artcam Technologies

Further, the present application may include the utilization of camera and data processing techniques such as an Artcam type device as described in the following Australian provisional patent specifications incorporated here by cross-reference:

Australian Provisional Number Filing Date Title PO7991 15 Jul. 1997 Image Processing Method and Apparatus (ART01) PO7988 15 Jul. 1997 Image Processing Method and Apparatus (ART02) PO7993 15 Jul. 1997 Image Processing Method and Apparatus (ART03) PO9395 23 Sep. 1997 Data Processing Method and Apparatus (ART04) PO8017 15 Jul. 1997 Image Processing Method and Apparatus (ART06) PO8014 15 Jul. 1997 Media Device (ART07) PO8025 15 Jul. 1997 Image Processing Method and Apparatus (ART08) PO8032 15 Jul. 1997 Image Processing Method and Apparatus (ART09) PO7999 15 Jul. 1997 Image Processing Method and Apparatus (ART10) PO7998 15 Jul. 1997 Image Processing Method and Apparatus (ART11) PO8031 15 Jul. 1997 Image Processing Method and Apparatus (ART12) PO8030 15 Jul. 1997 Media Device (ART13) PO7997 15 Jul. 1997 Media Device (ART15) PO7979 15 Jul. 1997 Media Device (ART16) PO8015 15 Jul. 1997 Media Device (ART17) PO7978 15 Jul. 1997 Media Device (ART18) PO7982 15 Jul 1997 Data Processing Method and Apparatus (ART 19) PO7989 15 Jul. 1997 Data Processing Method and Apparatus (ART20) PO8019 15 Jul. 1997 Media Processing Method and Apparatus (ART21) PO7980 15 Jul. 1997 Image Processing Method and Apparatus (ART22) PO8018 15 Jul. 1997 Image Processing Method and Apparatus (ART24) PO7938 15 Jul. 1997 Image Processing Method and Apparatus (ART25) PO8016 15 Jul. 1997 Image Processing Method and Apparatus (ART26) PO8024 15 Jul. 1997 Image Processing Method and Apparatus (ART27) PO7940 15 Jul. 1997 Data Processing Method and Apparatus (ART28) PO7939 15 Jul. 1997 Data Processing Method and Apparatus (ART29) PO8501 11 Aug. 1997 Image Processing Method and Apparatus (ART30) PO8500 11 Aug. 1997 Image Processing Method and Apparatus (ART31) PO7987 15 Jul. 1997 Data Processing Method and Apparatus (ART32) PO8022 15 Jul. 1997 Image Processing Method and Apparatus (ART33) PO8497 11 Aug. 1997 Image Processing Method and Apparatus (ART34) PO8020 15 Jul. 1997 Data Processing Method and Apparatus (ART38) PO8023 15 Jul. 1997 Data Processing Method and Apparatus (ART39) PO8504 11 Aug. 1997 Image Processing Method and Apparatus (ART42) PO8000 15 Jul. 1997 Data Processing Method and Apparatus (ART43) PO7977 15 Jul. 1997 Data Processing Method and Apparatus (ART44) PO7934 15 Jul. 1997 Data Processing Method and Apparatus (ART45) PO7990 15 Jul. 1997 Data Processing Method and Apparatus (ART46) PO8499 11 Aug. 1997 Image Processing Method and Apparatus (ART47) PO8502 11 Aug. 1997 Image Processing Method and Apparatus (ART48) PO7981 15 Jul. 1997 Data Processing Method and Apparatus (ART50) PO7986 15 Jul. 1997 Data Processing Method and Apparatus (ART51) PO7983 15 Jul. 1997 Data Processing Method and Apparatus (ART52) PO8026 15 Jul. 1997 Image Processing Method and Apparatus (ART53) PO8027 15 Jul. 1997 Image Processing Method and Apparatus (ART54) PO8028 15 Jul. 1997 Image Processing Method and Apparatus (ART56) PO9394 23 Sep. 1997 Image Processing Method and Apparatus (ART57) PO9396 23 Sep. 1997 Data Processing Method and Apparatus (ART58) PO9397 23 Sep. 1997 Data Processing Method and Apparatus (ART59) PO9398 23 Sep. 1997 Data Processing Method and Apparatus (ART60) PO9399 23 Sep. 1997 Data Processing Method and Apparatus (ART61) PO9400 23 Sep. 1997 Data Processing Method and Apparatus (ART62) PO9401 23 Sep. 1997 Data Processing Method and Apparatus (ART63) PO9402 23 Sep. 1997 Data Processing Method and Apparatus (ART64) PO9403 23 Sep. 1997 Data Processing Method and Apparatus (ART65) PO9405 23 Sep. 1997 Data Processing Method and Apparatus (ART66) PP0959 16 Dec. 1997 A Data Processing Method and Apparatus (ART68) PP1397 19 Jan. 1998 A Media Device (ART69) 

1. A digital camera comprising: a jacket; a viewfinder located within said jacket for selecting an image; an image sensor device located within said jacket for sensing said image; a processing means located within said jacket for processing said sensed image; a pagewidth print head located within said jacket for printing said sensed image; an ink supply means located within said jacket for supplying ink to the print head; a supply of print media on to which said image is printed, the supply of print media being pre-marked with tokens designating that postage has been paid so that each image printed out on the print media has one such token associated with it, the tokens being pre-printed at regularly spaced intervals on one surface of the print media.
 2. A digital camera according to claim 1 wherein each token has an address zone and a blank zone for writing associated with it on the one surface to provide a postcard effect.
 3. The camera of claim 1 in which the supply of print media is in the form of a roll, the tokens being pre-printed at regularly spaced intervals on one surface of the print media.
 4. The camera of claim 1 in which each image is printed on an opposed surface of the printed media.
 5. The camera of claim 1 in which the token is in a currency of a country in which the camera is bought, with a notice to that effect being carried on an exterior of the camera. 